flIL-HDBK-208Q
'3499770 02127b3 4 3 T
NOTE: MIL-SllJ-20&Q(AS) has been redesignated as
a handbook. and i s t o be used for guidance purposes
only. This document i s no longer t o be c i t e d as a
requirement. For administrative expediency, the
only physical changefrom HIL-STD-Z084(AS)i s t h i s
cover page. However, t h i s document i s no longer t o
be cited as a requirement. I f cited as a requirement
contractors may disregard t h e requirements o f t h i s
documentand interpret i t s contents on1y as guidance.
'i
1
NOT MEASUREMENT
SENSITIVE
MIL-HD6K-2084
31 J u l y 1995
SUPERSEDING
MIL-STD-Z084(AS)
06 April 1982
DEPARTIVIENT OF DEFENSE
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
HANDBOOK FOR
MAINTA1NABILITY OF AVIONIC AND ELECTRONIC
S Y S T E M S AND EQUIPMENT
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
j
MIL-HDBK-2R84 C H G NQTICE L
4499970 0232796 986
m
MIL-SID-Z0R4( AS)
NOTICE 1
14 June 1983
MILITARY STANDARD
GENERAL REQUIRKNTS FOR
MA IWTAINAB IL ITY OF AY IONIC AND ELECTRONIC
S Y S T E M AND EQUIPENT
To al 1 holders o f M!L-SID-Z084(AS)
1. The following pages o f
the pages 1 i s t e d :
Hew Page
104-3
104-4
2.
M I L-STD-Z084(AS have been
Da te
6 April 1982
14 June 19ß3
r e v i sed and supersede
na t e
Superseded Page
104-3
104-4
RETA1 W TK IS HOTICE AND INSERTBEFORE
Reprfnted w/o change
6 Aprl l 1982
TABLE OF COtKENTS.
Holders of FtIL-STD-Z1)84(AS) will verify t h a t the page changes indjcated
herin have been enternd. This notice will he retained I S a check S h e e t . This
iSSllance is a separate puhlicatfon. Each notice i s t o he retained by stockinp
p o i n t s until the Military Standard js completely revised or cancelled.
.
Preparl ng A c t i vi t y :
Navy As
-
(Project No. IWTY-NO03)
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
3.
DEPARRZENT OF THE NAVY
HAVAL AIR SYSTEMS COMMAND
Washington, D. C.
20361
General Requirements fo r M a i n t a i n a b i l i t y of Avionic and E l e c t r o n i c
Systems a n d EyuipmI-wt.
i.
T h i s X i l i t a r y Standard is approved f o r use by the Naval Air
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
s y s terns COI:IIW:-IC!, lkpartmc~nt of t h e Navy, and is a v a i l a b l e for use by a l l
Department.s a n d Agencies of t h e Department of Defense.
2 . B e n e f i c i a l comments (recommendations, a d d i t i o n s , d e l e t i o n s ) and
any p e r r s i n t n t datr? w h i c h may be of use in improving this document should
be addressed L O : C;omnanding O f f i c e r , Engineering S p e c i f i c a t i o n s and
Standards Department (Code 9 3 ) , Kaval Air EngineeringCenter,
Lakehurst,
NJ 05733, II?’ using the self-addressed Standardization Document Improvement Proposal
(DG Form 1416) appearing a t t h e end of t h i s document o r by l e t t e r .
li
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
MIL-HDBK-2084
= 9999970 0232765
202
H a í n t a i n a b i l i t y it3 an a t t r i b u t e of design and i a a measure of the ease,
r a p i d i t y , and accuracy v i t h which systems or equipment can be r e s t o r e d
t o o p e r a t i o n a l status following failure ar r e p a i r . A high degree of
readiness and a v a i l a b i l i t y of a v i o n i c and e l e c t r o n i c syetcmeandequipment
can be assured only when t h e i r design allow6 f o r positive and a c c u r a t e
i d e n t i f i c a t i o n of operational s t a t u a , and when items a r e found defectlve,
rapid end eff i c l e n t f a u l t í s o l a t i o n , removal,replacement, and eubaequeut
ro p a i r
b
The r p e c í a l f e a t u r e s designed and b u i l t into systems which make them
e m y t o auintain and e f f i c i e n t to support r e s u l t when maintainability I s
clearly deflned as a s y e t a n requirement and the n r a f n t a i ~ b i l i t y progrsm
i s established as a f u n c t i o n a l area of design. The purpose of t h i s
atandsrd l e n o t t o subrogate the maintainability progrsm requirement8
of
MIGSTD-470, but merely t o a m p l i f y the design c r i t e r i a r e q u i r e m e n t s of
t h e m a i n t a i n a b i l i t y program and t o emphasize m a i n t a i n a b i l i t y by design.
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
Under the concept of m a i n t a i n a b i l i t y by design, emphasis is placed on
t h o s e design areas which t e n d t o have the g r e a t e s t i n f l u e n c e on ease of
rartfntenance. T h l e Includesrequirementsformoduhrization,replacement
at
h i g h e r levelr, andincreased depth of l o c a l i z a t i o n , These physical and
t e c h n i c a l consideratione of maintainsbilitp design a r e n e c e s s a r y if
cmpll,r. cvianlc erd cltstrfl-ic s p s t m ~=c!eq-&ps: =re t=! be scppsrted
e f f i c i e n t l y a t a l l levels o f maintenance.
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
MXL-Sm2084 (AS)
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
CONTENTS
Paragraph
.
.....................
1
1.1
1.2
1.3
.....................
Application . . . . . . . . . . . . . . . . . .
.
.............
DEFINITIONS . . . . . . . . . . . . . . . . . .
Terms . . . . . . . . . . . . . . . . . . . . .
Shop replaceable assembly ( S U ) . . . . . . . .
Quick replaceable assembly (QU) . . . . . . .
Bench replaceable assembly (BRA) . . . . . . . .
Sub-shop replaceable assembly (sub-SM) . . . .
Weapons replaceable assembly (VRAI . . . . . .
GENERAL REQULREMmTS . . . . . . . . . . . . .
Application of requirements . . . . . . . . . .
DETAIL REQUIRMENTS . . . . . . . . . . . . . . .
Individual requirements . . . . . . . . . . . .
2
2.1
.
3
3.1
3.1.1
3.1.1.1
3.1.1.2
3.1.1.3
3.1.2
4
.
4.1
.
5
5.1
SCOPE
Scope
..............
Method of reference
REFERENCED DOCUKENTS
Issues of documents
Requirement
Requirement
Requirement
Requirement
Requirement
Requirement
101
102
103
104
105
106
Appendix A
.
.
10.2
10.3
30
2
2
2
2
3
3
3
3
3
3
3
Application Guide
Pape
...................
. . . . . . . . . . .. ..... .. .. .. .. .. .. .. . .
A-1
A-1
A-1
A-1
.....
A-1
.........
A-1
GENERAL.
.....................
Scope
Tailoring
requirements
User
REFERENCED DOCUMENTS (not applicable)
.
DEFINITIONS (not applicable)
daneshlink.com
daneshlink.com
1
1
Maintainability Program
Failure Hode a n d Effects Analysis
Physical Design
Built-Ln-Test
Test Points
Malntalnability Index
.
20
1
..............
Paragraph
10
10.1
1
1
1
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
U 999%970 02127b? 085
MIL-HDBK-2084
. .
MIGSTD-2084 (AS)
C O N T W T S (Continued)
Appendix A . Application Guide (Continued)
Paragraph
.
40
40.1
40.2
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
40.3
.
50
50.1
50.2
50.3
50.4
50.5
50.6
Page
.............
............
. . . . . . .. . .. ..
GENERAZ REQUIREMENTS
Requirements selection
A p p l i c a t i o n matrix f o r program phases
Requirement prioritization
DETAIL REQUIREHENTS
..............
...
...............
.......
Requirement 101 .Maintainability Program
Requirement 102
Failure Mode and Effects
Analysis (FMEA)
Requirement 103 .Physical Design
Requirement 104 .Built-Xn-Test (BIT)
Requiremenr 105 .Test Points
Requirement 106 .Maintainability Index
.
.....
.........
....
A-1
A-1
A-1
A-2
A-2
A-2
A-3
A-3
A-3
A 4
A-5
TABLES
Table
ì<onambiguous 5-BA i s o i a t i o n groups
Nonambiguous SRA isolation groups
Fault isolation groups within S M
Application matrix
.......
.......
.......
...............
V
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
104-4
105-2
105-3
h-2
MII.-STD-2084 (AS)
1.
SCOPE
1.1
Scope. T h i s s t a n d a r d cevers t h e comon maintainability
designrequirements t o b e us132 i n ~ i l i t a r yspecifications f o r avionic
and e l e c t r o n i c s::stems and equipment.
Applicacian. .,..
ilris standard il; a p p l i c a b l e to Kaval
Air Systems Corrmand procurements f o r t h e design and development of
a v i o n i c and e l e c t r o n i c systems 2nd cquipmmt. The requirements contained
herein are inKended t o provide urliform requirzments and s h a l l be incorporated
by reference in d e t a i l e d equi.prnent specifications. Other documents may
r e f e r e n c er e q u i r e m e n t s when applicable.
1.2
"
I
_
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
1.3
Method of r c f c"_." r c n r c . When s p e c i 2 y i n g requirements
o f t h i s s t a n d a r d , b o t h t h e standard and t h es p e c i f i cy e q u i r e m e n t
number(s)
are t o be c i t e d . Applicable "Dc-!tai!s
t o bp s p e c i f i e d " s h a l l be included
i n the Statement of Work. D e a i l s annotated by an " ( R ) " shall be provided
to t h e c o n t r a c t o r f o r p r o p e r i q l e m e n t a t i o n of therequirement.
2.
REFERENCD DOCLMEKTS
2.1
Issues of documents-. The f o l l o w i n g documents of the
i s s u e i n e f f e c t on tile d a t e of i n v i r a t i o r . f o r L.;<: o r rcquc-st f o r proposal,
a r e referenced i n t h i s s t a n d a r d f o r information and g u i d a n c e .
STANDARDS
Plilicary
MIL-STD-280
D e f i n i t i o n t of I t c m L e v d s , Item ExchangeaLi!itL., Modeis, and Related ï e m s
YIL-STD-Ai 1
MIL-STD-415
'Iest ? r c t v j + , i u n : , f o l i l e c t r i c s l Systems and
A s s o c i a t e d E q u i p m e n t , Design Criteria for
FIIL-STD-454
S t a n d a r d General kcquirements for E l e c t r o n i c
Ea I I i ?ment
MIL-STD- 72 1
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
~~
MIL-HDBK-2084
9 9 9 9 9 3 9 0232769 958
MIL-STD-2084 (AS)
MIL-STD-882
Svstem Safety Program Requirements
MIL-STD-1390 (AS)
Level of Repair
MIL-STD-1472
Ruman Engineering Design Criteria f o r
MilitarySystems, Equipment, and F a c i l i t i e s
MIL-STD-1629
Procedures
Performing
for
a Failure Mode,
E f f e c t s , and C r i t i c a l i t y Analysis
MXL-Sm-2068
Reliability Development Test
MIL-STD-2076
Unit 'Under Test C m p a t i b i l i t p v i t h Automatic
Test Equipment; General Requirements for
HANDBOOKS
Militarv
MIL-HDBK-472
Maintainabflfty Predtctfon
OTHER PUBLICATIONS
NAVMAT-P-9405
Built-h-Test
Design Guide
(Copies of specffications,standards,drawings,
and publicattons
required by contractors ln connectionwith spectfi'c procurement functions
should be obtained from the procuring a c t i v i t y or a8 directed by the
contracting o f f i c e r . )
3.
DEFINITIONS
3.1
Tenns. See each individual requirement f o r applicable
definitions v i t h the exception of t h e f o l l o w t n g whtch are applicable to
all requirements:
3.1.1
Shop replaceable assemblv (SF#$.
A generic tem
which includes a l l the packages w i t h i n a WRA including the chassis and
wiring a s a unit.
3.1.1.1
w i c k r e p l a c e a b l e assemblv (CIRA). A preferred form
of S M which is e a s i l y removable from the WRA withmt complex operations
or special tools and is typified by a plug-indesign.
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
STANDARDS (Continued 1
M I L - S T D - ~ O(AS)
~~
3.1.1.2
Bench r e p l a c e a b l e assembly (BRA). A less d e s i r a b l e
form of S U which is not e a s i l y removable; e.g.,e
m
t
I
bolted t o chassis
o r h e a t sink o r s o l d e r e d IR place.
3.1.1.3
Sub-shop r e p l a c e a b l e assembly ( s u b - S U ) .
A modular
irem packaged i n an SRA.
Weapons r e p l a c e a b l e assembly (URAL. A g e n e r i c t e m
which i n c l u d e s all replaceable packages of a system i n s t a l l e d in the
weapon system w i t h the exception of c a b l e s , mounting p r o v i s i o n s , and
fuse boxes or c i r c u i t breakers. The URh is g e n e r a l l y modular l n form
and designed t o f a c i l i t a t e an o r g a n i z a t i o n a l level removal and r e p l a c e
maintenance concept. The p r e f e r r e d form of WRA is the l i g h tr e p l a c e a b l e
assembly (LM) which is e a s i l y removed and replaced in the weapon system
by one man in not mote than 15 minutes.
3.1.2
4.
GENERAL REQUIRDBNTS
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
4.1
A p p l i c a t i o n of requirements. Requirements described
be
i n t h i s s t a n d a r d are to be s e l e c t i v e l y a p p l i e d and a r e i n t e n d e d t o
tailored as required and as a p p r o p r i a t e t o particular systems andequipment
programs. The purpose is t o p r o v i d ec r i t e r i a for f e a t u r e s which w i l l
minimize maintenance downtime, c o s t s , complexity, and personnel requirements.
5.
DETAIL R E Q U I I S
IsdiviG-l r c q u i r a n e n r s . i n d i v i d u a i requlreanents
for a v i o n i c and e l e c t r o n i cs y s t e m s and equipment ( e l e c t r o n i c system)
follow.
z
-.A
1
PreparingActivity
NAVY
- As
( P r o j e c t No. MNTY-NOO1)
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
3
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
MIL-STD-2084 (AS)
REQUIRPMENT 101
l4AINTAINABILITY PROCM
1,
Purpose. This requirement eetablishee criteria for tanks and
requiremente of a maintainability program.
Referenced documents. The following documente are applicable to
Requirement 101.
2.
STANDARDS
Military
MIL-STD-470
Maintainability Program Requlrements for
Systems and Equipment, Development and
Production
MIL- STD-4 7 I
Maintainability Verification/Demonstration/
ktaluarion
Definitions of T e m for Reliability and
Maintainability
HANDBOOKS
Military
MIL-HDBK-4 72
'
Maintainability
Prediction
3.
Definitions, Definitions applicable t o 'Requirement 101 are in
accordance w i t h MIL-STD-470, MIL-STD-471, MIL-EIDIE-472, ML-STD-721, and
Secrion 3 of this standard.
4.
Maintainability program. The tasks and requirements f o r a maintainability
program in accordance with
MIL-STP-470 shall be specified in the contract
statement of work.
4.1
Quantitative
maintainability
requirements.
Quantitative
maintainability requirements for organizational (O) level and intermediate
(I) level shall be specified i n the contract Statement of Work or equipment
specification. Unless otherwise specified, t h e maximum time to repair
( m x c t ) within which 95Z of all organizational corrective maintenance
actlons will be completed s h a l l not exceed thirty (30) minutes. Maximum
time to repair includes ail elements (e.g., verification, location,
repair, etc.) as defined in MIL-STD-471 a n d MIL-HDBK-472.
4.2
Maintainability
analysis.
A ?m~flltRin~tbility
a.nalySi8
shall be performed in accordance withMIL-STD-470 to develop the detailed
for the electronic
quantitative and qualitative maintainability requirements
system. Analyeis results shallbe used to allocate the maintainability
requirements t o lower indenture levels of the electronic system and to
update the design criteria and the maintenance p l a n .
Requirement 101
6 April 1982
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
101-1
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
4.3
Halntalnabilíty
prediction.
A maintainability
prediction shall be performed to estimate the quantitative maintainability
parameter values of the planned design configurationof the electronic
system. For prediction of organizational levelmaintainabílity values,
Procedure 1 of MIL-HDBK-472 shall be adapted f o r the particular design
and shall include only directmaintenance times. The effects of a
malfunction of built-in-test (BIT) and fault isolation functionsand a l l
preventive maintenance times, including calibration and adjustment
times, shall be included. Descriptions of the installation and removal
procedures for t h e electronic system s h a l l be prepared and s h a l l include
the f ollaring :
a.
The equipment mounts, including fasteners.
b.
Function a n d test connectors at weapon replaceable
assembly (WRA) and lower levels of assembly.
C.
All other aspects of equipment installation
such as cooling lines or ducts which will
influence maintenance time.
5.
Design crtterla a n d çsidelines. The contractor s h a l l develop
detail design criteria and guidelines in accordancew i t h MIL-STD-470 to
provide guidance for the integration of rdalntafnability enhancement
features into the electronic system design. Specific design guidance
s h a l l be provided f o r the areas of fault detection and i s o l a t i a ,
location and grouping of test points, interchangeability, and physical
accessibility for repair a n d replacement. The desigr, criteria and
guidelines shall be documented a n d made available to the procuring
activity or its designated representative
on request.
6.
D e t a i l s to be supplied. Details to be supplied
Work include the following, as BppliCabh.
in the Statement of
a.
Identification of each maintainability program
task in accordance withMIL-STD-470.
b.
Quantitative maintainability requirements for
organizational levela n d intermedfate l e v e l .
c. Delivery identification
of any data item required.
Requirement 101
6 April 1982
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
101-2
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
MIL-STD-2084 (As)
HfL-STD-2084 (AS)
1.
Purpose. This r e q u i r e m e n et s t a b l i s h e st h e
criteria f o rt h ef a i l u r e
mode a n d e f f e c t s a n a l y s f s of electroalc system to i d e n t i f y t h e necessary
d e s i g n c h a r a c t e r i s t i c s that m w t be r s c r l b e d to aaintainability.
2.
Referenced documents.
Requirement 102.
The folloving docmncnt ia a p p l i c a b l e t o
STANDARDS
Military
HIL-STD-1629
Procedures for Performing a F a i l u r e Node,
E f f e c t s , a n d C r i t i c a l i t y Analysis
3.
D e f i n i t i o n s . Definitione a p p l i c a b l et o
accordance w i t h MIL-STD-1629,
Requirement 102 a r e l n
4.
F a i l u r e mode a n d e f f e c t s analysis (FHEQ. An FMEA in accordance
w i t h KIL-STD-1629, Task 101, shall be u t i l i z e d to document probable
failures i n the electronic spstan und to determine t h e e f f e c t s of the
failures on e l e c t r o n i c system o p e r a t i o n . FMEA(s) s h a l l be performed t o
the le*.teL!s) specified ts ideztffy foil.;re =&CS, f s i k r e CZZ;ÔBS, a 2
f a i l u r ee f f e c t s .
This a n a l y s i s shall be scheduled and completed concurrently
with t h e design effort so that t h e design vil1 r e f l e c t analysis c m k l u s i o n s
and recommendations.
Failure mode, e f f e c t s , and c r i t i c a l i t y analvsis (FKECA)loalntainabilIty
information. An F'MECA-maintainability information analysis shall be
performed l na c c o r d a n c e w i t h MIL-STD-1629, Task 103. This analysis is
u t i l i z e d to provide early criteria f o r maintenanceplanninganalysis
(MPA), logistics support a n a l y s i s ( I S A ) , rtnd to i d e n t i f y m a i n t a i n a b i l i t y
design features r e q u i r i n gc o r r e c t i v ea c t i o n .
-A-maintainability
infororation analysis shall be perfolmed t o the l e v e l ( & ) s p e c i f i e d to
i d e n t i f y i n c i p i e n t failure i n d i c a t o r s , f a i l u r e d e t e c t i o n
means, failure
I s o l a t i o n means, and b a s i c maintenanceactions.
5.
6.
F'MECA results. The result and current s t a t u s of t h e PHEA and t h e
FMECA-maintainability information analysis shall be presented at 811
design reviews a n d shall be ueed 88 inputs to d e s i g n t r a d e - o f f s , MPA's,
L S A ' s , test equipment design, t e ~ planning,
t
and inspection and checkout
planning. These r e s u l t s afia11 be ueed during the b u i l t - i n - t e s t (BIT)
and test point design t o determine:
Requirement 102
6 Apri 1 1982
102-1
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
MIL-STD-2084 (AS)
a.
The type of faultdetection
means.
b.
A t what points fault
i
and ieolation
detection and i s o l a t i o n ,
t o single Item or group of items, CM be
implemented.
C.
Proportion of fault8 ln each single Itam or
group of iterne detectable by the proposed
dcaign 8pproach.
d.
Proportion of detectable faults which CUI be
Isolatedto a single ítem or group of ltema by
the proposed design approach.
7,
Details t o be specified. Details t o be specified in the Statomcat
of Work shall include the following aa applicable:
Identification of the level to which FHEA shall
be conducted.
Identification of maintenance l e v e l s for which
FMEA l e to be performed.
C.
Logletic supportcoordlnatedreporting
for l o g i o t i c support analysis.
d.
Identification of maintenance plan(s) and
support requirements.
e.
Identification of reviews required.
f.
Delivery Identification
requirements
of any dato Item required.
Requirement 102
6 April 1982
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
102-2
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
~-
MIL-HDBK-2084
9999970 0232775 351
REQUIREHENT 103
PHYSICAL DESIGN
1.
Purpose. This requirement establishes criteria f o r the design o f
the physical characteristics which influence the maintainability features
and maintenance requirements of the electronic system.
2.
Referenced documents.
Requirement 103.
The following
docments
are applicable to
Militarv
XIL-STD-280
Definitions of Item Levels, Item Exchangeability,
Models,’ a n d Related Terms
MIL- STD-4 54
Standard General Requirements f o r E l e c t r o n i c
Equipment
MIL-STD-1390
Level of Repair
(law)
3.
Definitions. Definitions applicable to Requirement 103 arc in
accordance w i t h MIL-Sm-280, MIL-STD-454, MIL-STD-1390. and S e c t i n n 3 of
t h i s standard,
4.
Design. The electronicsystem shall be designed to provide functional
and physicalpartitioning at all levels of assembly to e n a b l e m o d u l a r
packaging of assemblies a n d subassemblies i n t o weapons r e p l a c e a h l e
assemblies (W) and shop replaceable assemblies ( S ” h k ) .
Consideration
shall be given to designing c i r c u i t s i n t od i s c r e t e functional packages
of such cost a n d r e l i a b i l i t y that discard at failure rather than module
r e p a i r is the most cost-effective logistic support action. A level of
repair (LOR) analysis shall be u t i l i z e d t o e s t a t l i s h t h e most c a s t effective method of logisricalfy supporting the electronic systen.
4.1
Weapons repiaceable assembly ( W U ) . Each WKA shall
be desigmed and constructed as t h e l e a s t complex assembly of t’ne weapon
system v h i c h can be removed and replaced as a moduiar pí!ckaf;e at t n r Organizational l e v e l of malnrenance. Physical measures shall be provjded
( e . & ., alignment pins, .keying, e t c . ) t o precludeinterchange
of W s n i
similar form which are not functiondly intzrchangeablc and t o preclude
i m p r o p e r m o u n t i n g at Installation. As a designobjective,
thcJ d e s i g n
weight Of each WRA ehali be less than 40 pounds. Thedeojgn weight of a
W shall never exceed 80 pounds.
103-1
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
~~
MIL-HDBK-2084
= 9999970
0 2 1 2 7 7 6 O98
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
4.2
Shop replaceable aesemblp (SU), Each SRA ahall be
designed and c o n s t r u c t e d for removal and replacement i n a WRA as a
modularpackage.
To the maximum e x t e n t practicable, each S U shall be
designed into discrete functional packages for d i s c a r d at failure r a t h e r
t h a n repair. The maintenance criteria for d i s c a r d a t failure or repafr
s h a l l be e s t a b l i s h e dt h r o u g h LOR a n a l y s i s . P h y s i c a l
measures shalr be
provided (e.g., alignment p i n s , keying, e t c . ) t o preclude Interchange of
S M ' S of similar form which are n o t f u n c t i o n a l l y i n t e r c h a n g e a b l e
and t o
preclude improper mounting at installation.
Quick
replaceable
assembly (QU)Each QRA W i n g 8
p l u g - i n i n t e r f a c e and connection with a WRA shall be designed t o be
removed and r e p l a c e d with ease of physical e f f o r t and without inducing
m a i n t e n a n c er e l a t e df a i l u r e s .S p e c i f i c a l l y ,t h e
QRA shall be deeigned
t o be removed withoutdisassembly and w i t h o u t d i s t u r b i n g elements of
a d j a c e n tI n s t a l l a t i o n s .
The plug-in design shall p r e c l u d et h e possibility
that f o r c e t o e f f e c t
removalandreplacenrent
can be a p p l i e d w i t h hand or
d e s i g n a t e d t o o l in d i r e c t c o n t a c t with a p a r t , component, or c i r c u i t of
t h e QU,
a d j a c e n t SRAS, or WRA, Maintenance procedure provFsims or
caurion notes s h a l l not be s u f f i c i e n t to satisfy t h i s requirement.
S p e c i a l t o o l s shall not be r e q u i r e dt o remove or r e p l a c e QRAs.
4.2.1
4.2.2
Bench replaceable assembly {BRA). Each BRA shall be
d e s i g n e d a n d c o n s t r u c t e d t o conform t o t h e i n t e r n a l w i r i n g
practices
c r i t e r i a of HIL-STD-454, Requirement 69.
4.2.3
Subshop replaceable assemblv (sub-SM). Each subS M s h a l l be designed, t o t h e maximum e x t e n t p r a c t i c a b l e , i n t o d i s c r e t e
functionalpackages for d i s c a r d at failure rather than repair. The
maintenance c r i t e r i a for d i s c a r d at f a i l u r e or repair shall be e s t a b l i e h e d
t h r o u g h LOR analysis.
4.3
I n t e r c h a n g e a b i l i t y . All îtema i n t h e e l e c t r o n i c
system s h a l l be designed, selected, and a p p l i e d in a c c o r d a n c e v i t h the
c r i t e r i a f o r i n t e r c h a n g e a b i l i t y of HfL-STD-454, Requirement 7.
4.4
Conformal coating.
Materiale
used
for c o n f o n d
c o a t i n g shall be i n accordance w i t h t h ea p p l i c a b l ed e s i g n
requirements
s p e c i f i e d i n theequipmentspecification.
No conformalcoatingmaterial
s h a l l be a p p l i e d t o test p o i n t s .
4.5
Encapsulation a n d embedment. No e n c a p s u l a t i o n or
embedment material Shall be a p p l i e d t o reparsble modules, aseemblies, or
subassemblies.
A c c e s s i b i l i t yA
. c c e s s i b i l i t yr e q u i r e m e n t s
for a l l reparable îtem
i n the e l e c t r o n i c system shall be i n accordance with the criteria of
Requd rement 36 of MIL-STD-454. A c c e s s i b i l i t yc o n e i d e r a t i o n ss h a l l
include:
5.
Requirement 103
6 April 1982
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
103-2
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
MIL-HDBK-2084
U 9999970 023237? T 2 4
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
and diversity of fasteners
commensurate with specific design requirements
Hand-operated fastenersare preferred and
fasteners requiring use of common tools are
acceptable. Fasteners requiring special t o o l s
shall not be used.
a.
A minimum number
b.
Access openings s h a l l be sufficiently large for
visual inspections and manipulative a c t i o n s for
adjusting, removal, and handling.
C .
A
sufficient number of accessible test points
shall be provided so it is not necessary to
remove assemblies or subassemblies to accomplish
testing.
Elapseà time indicators. Elapsed time indicators (ETI) shall be
easily read with the WRA in its n o r m a l l y i n s t a l l e d position in the
weapon system. Electrochemical ETIs s h a l l not be used.
6.
7.
Protective d e v i c e s . Circuit breakers shall be used in l i e u of
fuses and shall be accessible from the exterior of each WRA w i t h the WRE.
in its n o r m a l l y i n s r a l l e d position in the weapon system. C i r c u i t breakers
will be of the fault indicating typea n d shall be p l z i n l y marked as to
r a t i n g and s i z e .
6.
Derails t o be specified. Details t o be s p e c i f i e d in the Statement
of Work s h a l l include the folioKing,as applicable.
a.
Specification of policies o r guidance to be
considered for use in guiding the design process.
b.
Specification of particular Government o r
Industry Handbooks tobe utilized.
c
Logistic support coordinated r e p o r t i n g requirements
for logistic support analysis.
d.
Information available from procuring activity (PA)
relative to constraints on system or equipment
due to personnel, physical location, use
environment, or maintenance concept.
e.
Lists of standard tools and equipment.
i.
Delivery identification of any data items
required.
L .
Requiremnt 103
6 April 1982
103-3
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
~
REQUIRPWT 104
BUILT-IN-TEST
1.
Purpose. This requirement establishes criteria for design and
application of built-in-test (BIT) which will adequately support the
defined maintenance concept.
2.
Referenced documents.
Requirement 104.
The following d ~ u m e n t 6are applicable to
STANDARDS
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
HIC-STD-411
Aircrew Station Signals
MIL-STD-454
Standard General Requirements for Electronic
Equipment
MIL-STD-470
Maintalnabilitv Program Requirements f o r S y s t e m s
and Equipment, Development and Production
MIL-STD-882
System Safetv Program ,Requirements
MIL-STD-1472
Human Engineering Destgn Criteria for Wllltary
Svetems, Equipment, and Facflfties
MIL-STD-1629
Procedures for Performing a Psilnre Mode,
Effects, and Crixicality Analvsis
MIL-STD-2068
Reltabilitv Development Test
OTHER PUBLICATIONS
NAVHAT-P-9405
Built-In-Test
Design Guide
Definitions. Definitions a p p l i c a b l e to Requirement 104 are ir.
accordance with MIL-Sn-411, MIL-STD-454, MIL-STD-470, HIL-STD-862, MILSTD-1472, MIL-STD-1629, MIL-STD-2068, and S e c t i o n 3 of t h i s standard
with t h e excepcion an¿ addi'tton of the following:
3.
Requirement -104
6 Apri 1 1982
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
MIL-STD-2084 (AS)
3.1
Built-in-test ('BIT).. The s e l f t e s t hardware and
s o f t w a r e which is i n t e r n a l t o a unit t o test the unit.
3.2
Built-in-test-equipment
(BITE). A u n i t which is a
p a r t of a systemland i 5 used f o r t h e express purpose of t e s t i n g t h e
system. BITE is an i d e n t i f i a b l eu n i t of a system.
3.3
t h e MIL-STD-882
Mission c r i t i c a l f a i l u r e . A f a i l u r e which includes
h a z a r ds e v e r i t yc a t e g o r i e s
of c a t a s t r o p h i c a n d c r i t i c a l .
3.4
Operational
readiness
t e s t . That set of f u n c t i o n a l
tests and o b s e r v a t i o n sn e c e s s a r yf o rt h ef l i g h r
crew todetermine the
o p e r a t i o n a l u s a b i l i t y of a system.
3.5
Sensor. A d e vdi cees i g ni ne tdo
a system
which
c o n v e r t s a p a r t i c u l a r p a r a m e t e r i n t o a form s u i t a b l e f o r measurement by
test equipment.
Sensor,
active.
3.5.1
A s e n sr o
eq
r uiring
a source o f
power otherthanthesignalbeingmeasured.
3.5.2
power o t h e r t h a n
Sensor, passive. A s e n sroe rq u i r i n g
t h e s i g n a l beingmeasured.
3.6
Stimulus.
no source
Any p h y s i c a l or e l e c t r iicnaplu r
Of
applied
t o a d e v i c e inrended to produce a measurableresponse.
4.
B u i l t - i n - t e s t (BIT). BIT as consideredherein
i s an i n t e g r a l p a r t
of eachunit of the e l e c t r o n i c system which may be removable but which
does not o p e r a t e out of t h e system environment. Built-in-testequipment
(BITE) which i s defined as an i d e n t i f i a b l e unit of a system i s not
consideredherein except as related t o BIT.
4.1
Purpose of BIT. BI? shall be u t i l i z teod
provide an
i n d i c a t i o n of e l e c t r o n i c system performance and t op e r m i t f a u l t d e t e c t i o n
and i s o l a t i o nt o t h e r e p l a c e a b l e module or f u n c t i o n a le n t i t y .
BIT s h a l l
be compatible w i t h the e l e c t r o n i c systerc c i r c u i t r y t o minimize p o s s i b l e
l o s s of performanceoccasioned by i t s use.
4.2
B I T test p o i n t s . B I T test p o i n t s shall be selected
on t h e i r a b i l i t y t o d e t e c t and i s o l a t e f a u l t s w i t h a maximum degree of
confidence to the lowest p r a c t i c a b l e hardware level.Performancemonitoring
and f a u l t d e t e c t i o n and I s o l a t i o n at a p o i n t shall be a v a i l a b l e from a
s i n g l e sensor. I n the e v e n tt h a ts e n s i n gc i r c u i t r yn e c c e s s a r y
to monitor
t h e key parameter(s) of the signal would degradetheperformance
of t h e
c i r c u i t , would be d i f f i c u l t t o i n s t a l l , OY would s e r i o u s l y degrade
Requirement 104
6 April 1982
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
104-2
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
3.7
T e s t a b i l i t v . A c h a r a c t e r i s t i c of a n item's design
of t h a t item
wnich allows the s t a t u s( o p e r a b l e ,i n o p e r a b l e ,o rd e g r a d e d )
t o be confidentlydetermined i n a t i m e l y manner.
MIL-STD-2084 (
As)
r
'
..
:.
.
'
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
r e l i a b i l i t yc, o n s i d e r a t i o snh a lbl ge i v e tno b t a i n i n tgh ien f o r m a t i o n
t h r o u g he v a l u a t i o n of a group of i n t e r r e l a t e d test p o i n t s . P r i o r i t y
shallbegiventothetesting
of f u n c t i o n s t h a t are most important to
are b a s i c t o f a u l t d i a g n o s i s ,
and are.
t h eo p e r a t i o n a lm i s s i o n ,t h a t
l e a s t r e l i a b l e o r least a c c e s s i b l e .
B I T design. BIT s h a l l be designed as a ni n t e g r a lp a r t
of t h e
5.
BIT f u n c t i o n ss h a l lb ep e r f o r m e do n - l i n e
by
e l e c t r o n i cs y s t e md e s i g n .
e x e r c i s i n g componentsand c i r c u i t r y w i t h i n t h e e l e c t r o n i c s y s t e m s
by u s e
BIT s h a l l
ofsoftware a n dh a r d w a r es t i m u l io rm o n i t o r i n gc i r c u i t s .
r e q u i r e n o external s t i m u l i o r measurementequipment t o perform i t s
f u n c t i o n . The requiredperformance of an item s h a l l n o t b e d e g r a d e d
by
t h ed e s i g no rt h eu s e
of BIT. Guidance i n t h e a p p l i c a t i o n of BIT t o t h e
e l e c t r o n i c s y s t e m may befound i n NARIAT-P-9405.
Operational
5.1 readiness
tests. BIT c i r c u i t r y and
modes
d e v i c e s shall bedesigned t o test t h e e l e c t r o n i c s y s t e m o p e r a t i n g
a n d f u r n i s h &I i n d i c a t i o n of the 'operational readiness of the system.
n
The o p e r a t i o n a l r e a d i n e s s test s h a l i bedesigned t o b e f u n c t i o n a l i
boththemissionandmaintenanceenvironments.
The B I T f e a t u r e s u t i l i z e d
for operational readiness testing shall be designed to evaluate the
electronic system without need for external stimuli or
test equipment.
P e r f o r m a n c eb e l o wa c c e p t a b l el e v e l sa n d ,t ot h ee x t e n tp r a c t i c a b l e ,
marginal or degraded functions shall result
i n an a d v i s o r y o r c a u t i o n
a t t h e aircrew s t a t i o n .
indicatorbeingenergized
5.1.1
Automatic i n i t i a t i o n . The o p e r a t i or enaadl i n e s s
test shall be designed for automatic initiation
when t h e e l e c t r o n i c
system i s e n e r g i z e d (power ON) and at p e r i o d i c i n t e r v a l s d u r i n g o p e r a t i o n
i n i t i a t i o n is
u n l e s s i t canbe shownby a n a l y s i s t h a t on-demand,manual
more p r a c t i c a l .U n l e s so t h e r w i s es p e c i f i e d ,c o n t i n u o u sm o n i t o r i n go r
o p e r a t i o n a l t e s t i n g s h a l l be p r o v i d e d d u r i n g t h e e l e c t r o n i c s y s t e m
items which c o n t a i n m i s s i o n c r i t i c a l f a i l u r e modes.
operation for those
The c o n t i n u o u s m o n i t o r i n g o r o p e r a t i o n a l t e s t i n g
of o t h e r items w i t h i n
the electronic systems shall
beon a selective b a s i s j u s t i f i e d by an
a n a l y s i s which considers both the
BIT f a l s e alarm rate and theconsequences
of B I T f a i l u r e .
5.1.2
Manual i n i t i a t i o n . When manual i n i t i a t i o n i s bt oe
u t i l i z e d , a s w i t c h s h a l l be i n c o r p o r a t e d i n t h e e l e c t r o n i c s y s t e m c o n t r o l
test.
panelforinitiatingtheoperationalreadiness
5.1.3
Remote i n i t i a t i oPnr.o v i s i osnhsa l l
included
be
in
theoperationalreadiness
test c i r c u i t r y f o r t h e u s e o f
a remote s i g n a l
toinitiatetesting.
To t h ee x t e n tp r a c t i c a b l e ,
a p r o v i s i o ns h a l la l s o
beincludedforinhibitingtheoperationalreadiness
test by means of a
r e m o t es i g n a l .
Requirement 104
6 April 1982
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
'
..............
....
..
MIL-STD-2084(AS
.~..
.
..
.
.- .
5.2
F a u ldt e t e c t i o n
and i s o l a t i o n . The B I T d e s i g n
s h a ipl r o v i d e
a
c a p a b i l i t y f o r f a u l t d e t e c t i o n and i s o l a t i o n of t h e f a u l t t o a d e f e c t i v e W R A
o r SRA. No e x t e r n a l - s t i m u l i o r test equipment s h a l l b e r e q u i r e d t o p e r f o r m
t h e ß I T f a u l t d e t e c t i o n and i s o l a t i o n f u n c t i o n .
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
5.2.1
BIT f a u l td e t e c t i o nl e v e l .
The B I T d e s i g ns h a l lp r o v i d e
a fault
d e t e c t i o n f u n c t i o n as a GO/NO GO v i s u a l i n d i c a t i o n .
Unless o t h e r w i s e
s p e c i f i e d , B I T s h a l l d e t e c t f a i l u r e and outof-tolerance modes which represent
a t least 98 petcent of all e l e c t r o n i c s y s t e m f a u l t s . A n a l y t i c a l e s t i m a t e S . o f
design compliance with B I T d e t e c t a b i l i t y r e q u i r e m e n t s s h a l l b e a c o n s i d e r a t i o n
a t a l l d e s i g n reviews.
5.2.2
B I T f a u l ti s o l a t i o nl e v e l .
The B I T d e s i g ns h a l pl r o v i d e
a
f a i l u r e and out-of-tolerance
mode i s o l a t i o n a n d i d e n t i f i c a t i o n f u n c t i o n s
by
A t least 99 percentof
meansof
t h e B I T c i r c u i t r y ,d e v i c e s ,a n di n d i c a t o r s .
a l l e l e c t r o n i c s y s t e m f a i l u r e and out-of-tolerance modes d e t e c t e d a t
o r g a n i z a t i o n a l l e v e l m a i n t e n a n c e s h a l l .be ï s o l a t e d and i d e n t i f i e d w i t h o u t
ambiguity to the faulty
W R A by BIT.
The percentage of a l l WRA f a u l t s which
s h a l l b e i s o l a t e d and i d e n t i f i e d by B I T t o t h e f a u l t y SRA, o r small groupof
SRAs, s h a l l b e as l i s t e d i n t h e T a b l e
104-1. A n a l y t i c a l estimates of d e s i g n
compliance with B I T f a u l t i s o l a t i o n r e q u i r e m e n t s s h a l l b e a c o n s i d e r a t i o n a t
a l l design reviews.
-.
.
Table 104-1.
Nonambiguous SRA i s o l a t i o n groups
I
I
SRA AMBI QJITY GROUP
PERCENT OF W R A
FAULTSISOLATED
SM'S per W R A < 10
SIZE
SM'S per W R A > 10
100 percent
- 6 SRAs
95 percent
-< 5
SRAS
< 7 SRAS
-< 6 SRAs
90 percent
-< 4 SRAS
-< 5 SRAS
85 percent
80 percent
< 3 SRAS
-< 2 SRAS
-< 4 SRAS
-< 2 SRAS
75 percent
= 1
= 1 SRAS
SRAS
5.3
Design
growth
l i m i t . The g r o w tohtfheel e c t r o n iscy s t e m
design
due t o t h e i n c o r p o r a t i o n of BIT c i r c u i t r y a n d d e v i c e s s h a l l not exceed 10
peetlrhecoeceftnr o
ts ny isct ei rmc u ipgaqr ,t s ,
and devices.
.. .
'
.
. "i-'
Requirement 104
1 4 June 1983
. .
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
*US. GOVERNMENT
PRINTING
OFFICE: 1983- 606-034/3188
104-4
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
-
. . .
,
. '. 'i
6.
BIT r e l t a b i l i t l . R e l i a b i l i t y of BKT circuitry and devices shall be
an a l l o c a t e d portion of the electronicsystem, WRA, or SW r e l i a b i l i t y .
I n no case s h a l l the apportioned failure rate of the BIT circuitry a n d
devlces exceed 10 percent of the failure rate of the item or function
being monitored.
7.
False alarm rate. The probability of f a l s e indications of e l e c t r o n i c
system failures, consideringboth the electronic system and BIT, shall
n o t exceed one percent of all BIT i n d i c a t e d failures.
0.
BIT s e l f - t e s t . Self-test provisions shall be incorporated I n t o the
e l e c t r o n i c system as a means of testing the operational status of BlT
a n d BIT c i r c u i t r y 85 well as 8 means of ensuring unambigwus BIT readoute.
The maximum time for accomplishing the s e l f - t e s t s h a l l be specified ia
t h e e l e c t r o n i c system specification.
9.
BIT c a l i b r a t i o n . BIT circuits which contain reference circuits or
measurement devices s h a l l be provided with test p o i n t s v h i c h allow
i s o l a t i o n from the e l e c t r o n i c s y s t e m c i r c u i t r y a n d p e r m i t i n j e c t i o n of
t e s t signals. Adjustments to these reference c i r c u i t s o r measurement
devices s h a l l be readily accessible and f a u l t i n d i c a t i o n devices s h a l l
be v i s u a l l y accessible while adjustments are being performed,
10. Fail-safe provisions. The circuits and devices which provlde BIT
and f a u l t i s o l a t i o n f u n c t i o n s s h a l l be designed so that failure of these
c i r c u i t s or devices will nct c a s o , 3 'fail.;rc sf : b ~ d..zctrÛriic systsr,.
The following c r i t e r i a s h a l l a p p l y :
a.
Switches shall not be placed in series psths
for purposes of i n t r o d u c i n g stimuli, i n t r o d u c i n g
normal s i g n a l s , ar measuring systemperformance.
b.
I s o l a t i o n shall be provided at signal functions
w i t h BIT circuitry and devices and other f a u l t
isolation c i r c u i t r y s u c ht h a t normal BIT or
o t h e r t e s t operations will not affect system
performance, nor vil1 failure of BIT interfere
w i t h sps tem operation,
C.
BIT stimuli s h a l l be selected such t h a t Bystem
perfonpance degredation is minimized l n t h e
presence of the stimuli.
I n d i c a t o r s .I n d i c a t o r s
shall be u t i l i z e d to provide clear I n d i c a t i o n s
electronic s y s t e m operational r e a d i n e s s and fault locations. lndi~atOr8
selected shall comply w t t h the requirements of MIL-STD-1472. For integrate¿
or multi-mode systems, i n d i c a t o r s for t h è various subsystems and equipment
may be grouped together in an electronic syatem readiness advisory
panel.
11.
Of
Requirement 104
6 April 1982
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
106-5
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
HIL-STD-2084 (AS)
MIL-HDBK-20BY
MIL-STD-2084 (As)
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
11.1
Aircrew s t aitnl do inc a t o r s .
Electronic system
s t a t u s and c a u t i o n o r w a r n i n g i n d i c a t o r s s h a l l
be designed and a p p l i e d
of MIL-STD-411. The system status
i n accordancewiththerequirements
i n d i c a t o r s shall provide GO/NO GO i n d i c a t i o n s of system readiness or
functionalstatus.
11.2
F ianudl ti c a t F
o iarnsu.dl ti c a st ochorasnl lt i n u o u s l y
s e n s e f a u l t s i g n a l s and p r o v i d ei n d i c a t i o n s at t h e aircrew s t a t i o n and,
as r e q u i r e d , a t t h e WRA o r SRA l e v e l . BIT f a u l tl o c a t i o nf e a t u r e s
shall
e n e r g i z e a GO/NO GO d e v i c e l o c a t e d a t t h e WRA and, t o t h e e x t e n t p r a c t i c a b l e ,
a t t h e SRA. Fault l o c a t i o ni n d i c a t o r s at t h e WRA l e v e l shall be capable
o f holdingthe last test result i f power is i n t e r r u p t e d o r removed. All
f a u l t l o c a t i o n i n d i c a t o r s shall be v i s i b l e to maintenance personnel with
t h e item in i t s n o r m a l l y i n s t a l l e d p o s i t i o n .
11.3
Maintenance p a n e l . One of t h e WRAs provided for an
i n t e g r a t e d o r multi-mode e l e c t r o n i c system m y be a maintenance panel.
Vnen provided, a maintenancepanel shall be placed i n a weapon system so
i t may be readily v i e w e d a n d operated by maintenancepersonnel w i t h a l l
WRAs i n t h e i r n o r m a l l yi n s t a l l e dp o s i t i o n .
A maintenancepanelshall,
as a minimum, c o n s i s t of a group of several visual f a u l t i n d i c a t o r s
which w i l l i n d i c a t e t o maintenance personnel which WRA has malfunctioned.
Ta reducethe number of indicatorsrequired,themaintenancepanel
may
c o n t a i n a s w i t c h ( e s ) and a f a i l u r e summary i n d i c a t o r ( s ) which is independent
of s w i t c h p o s i t i o n .
Sensors. Passive sensors s h a l l be used i np r e f e r e n c e to a c t i v e
sensors wherever possible. Where active sensors are u s e d t o provide t h e
necessaryinformationnotobtainable
from p a s s i v es e n s o r s ,t h e r e
shall
be minimal e f f e c t on t h e r e l i a b i l i t y of thecircuit-sensorcombination.
12.
12.1
C a l i b r a t i o n . The use of sensors r e q u i r ci na gl i b r a t i o n ,
i n i t i a l or o t h e w i s e , s h a l l be avoided.
12.2
S h i e l d i n g . All s e n s os rhsa l l
be designed s o t h a t
i n t e r f e r e n c e caused by e l e c t r o m a g n e t i cr a d i a t i o n i s minimized through
t h e use of good d e s i g n p r i n c i p l e s and by f i l t e r i n g o r s h i e l d i n g as
r e q u i r e d . Electromagnetic interferencerequiremenrs
of t h ee l e c t r o n i c
system s p e c i f i c a t i o n shall a p p l y .
13. B I T f a u l td e t e c t i o n and i s o l a t i o n l e v e l verification. When r e l i a b i l i t y
development tests i n accordance w i t h MXL-STD-Z068(AS) a r e r e q u i r e d by
conrract, t h e c o n t r a c t o r shall niaintain a record of all f a i i u r e s and
developdata t o verify t h e WRA and SRA f a u l t d e t e c t i o n and i s o l a t i o n
requirements. On theoccurrence of an e l e c t r o n i cs y s t e mf a i l u r e ,t h e
3 I T f u n c t i o n shall be e x e r c i s e d and a record made i n t h e test log and i n
the f a i l u r e r e p o r t of B I T c a p a b i l i t y t o ' f a u l t d e t e c t
and fault i s o l a t e
During r e p a i r and
inaccordance with t h i sr e q u i r e m e n t .
?zquirement 104
5 April 1982
104-6
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
MIL-Sm-2084 (AS)
troubleehmtfng, BIT capability t o f a u l t isolate t o the faulty SRA shall
be recorded. BIT f a i l u r e s or t h e inability of BIT t o d e t e c t or i s o l a t e
f a i l u r e s shall be reported and Investigated in accordance with the
f a i l u r e reporting, analyeis, and c o r r e c t i v ea c t i o nr e q u i r e m e n t s
of MILST”2068(AS). Qe failure suannary r e p o r tr e q u i r e d by c o n t r a c t shall
i n c l u d e the l i s t i n g ß of al1 reported BIT f a i l u r e s and malfunctions.
Data from all primary system f a i l u r e s occurring during the reliability
development t e e t ehrll be used to evaluate WRA and S A f a u l t detection
and isolation requirements. These data shall be summarized and reported
in the reliability t e e t rerults reports.
14. Details to be specified. Details t o be s p e c i f i e d i n the Statement
of Work s h a l l Include the following, 88 a p p l i c a b l e .
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
B.
I d e n t i f i c a t i o n of maintenance a n d support
concepts,
b.
Ptojected f a c i l i t y t, r a i n i n g
program, s k i l l s ,
and equipment availability.
C.
S p e c i f i c a t i s n of p a r t i c u l acr o n t i n u o u s
o r o p e r a t i o n a l r e s t i n g requirements.
d.
S p e c i f i c a t i o n failure and out-of-tolerance
detection requirements.
e.
S p e c i f i c a t i o n of m
x
i
m
u
n
: BIT self-test time.
f.
S p e c i f i c a t i o n of a r e l i a b i l i t y development tes:
in accordance w i t h MZL-STD-2068 (AS).
g.
I d e n t i f i c a t i o n of t e s t a t t r i b u t e data t o be
reported (proportion of detection, percent
i s o l a t i o n , false alarm rate, ambiguity, e t c . )
h.
Delivery i d e n t i f i c a t i o n of any d a t a items
required.
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
104-7
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
monitoring
mode
1
Purgom. T h l r rrquiremrrnt establishes the criteria f o r t h e deeign
end appUcation of t e s t points which will adequately eupport the defined
maintenance concept.
2,
Referenced doculPLnta.
Requitunent 10s.
The foll4wing documente ate applicable to
STANDARDS
Hilitpry
H f t S m 4 15
Teet Provisions for Electrical Syeteme and
Aesocíated Equfpment, Design Criteria for
MIGSTD-454
Standard General
Requirements
Equipment
MIGSTP2076
Unit Under Test Compatibility with Automatic
Test Equipment; General Requirements for
for Electronic
3.
Definitions. Definitions sppllcable to Requirement 105 are in
8ccordanct v i t h HIL-ETb415, ?!A.LI-,S?!2-454,
?CL-,SI?-28?6,
Srrtiü,n 3 of
this standard.
4. Tesr pointa. Both external and internaltest
points shall be
provided which will permit the functionel and static parameters of an
electronic syetem t o be monitored, evaluated, and I s o l a t e d . The number
Of t e s t points shall be k e p t to a m i n i m but s u f f i c i e n t to provide the
ecope of maintenuncc required by the defined maintenance concept.
5.
D e e i ~ , Teet points shall be designed 88 an integral part of the
electronic system design in accordance with this requirement and MILSTD-415. Tset points provided shall permit q u a n t i t a t i v et e s t i n g , performsnce
monitoring, fault i s o l a t i o n , and calibration or alignment. Test point
compatibility with the designated or pianned Automatic T e s t Equipment
(ATE) ehall be in accordance kdth MIL-STD-2076.
5. I
External test points.
External
test points shall be
grouped, t o the extent practicable, l n 8 single multl-pin connector
which i e readily accessible on the surface of each WRA to permit t e s t i n g
while the WRA i s i n its normally i n s t s l l e d position in the weapon syetem
and without need for disconnecting operational connectors. Unless
othewiee epeclfied, external test points shall be provided for the
functional checkout and monitoring of the electronic eystem and f o r WRA
and S U falt: isolation, To the extent practicable, the functional and
fault isolation t e e t points shall be combined in a singleconnector.
All external t e s t p o i n t connectore shall be provided with captive caps.
Requirement 105
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
105-1
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
6 Apri 1 1982
~~
MIL-HDBK-2084
9999970 0 2 L 2 7 8 b T37
5.2
O r g a n i z a t i o n a l level test p o i n t s . The external test
pointsshallpermitapplication
of external f u n c t i o n a l e t i m u l i for
conductlng en¿-to-end quantitative checkouts and measurements of the
electronicsystemfunctionalperformance.
The f a u l t i s o l a t i o n t e s t
p o i n t s shall permit unmnbiguoua f a u l t i s o l a t i o n , c a l i b r a t i o n
o r all-t
o f W , and c h e c k o u t o r c a l i b r a t i o n
of BIT while t h e WRAs are i n s t a l l e d
in t h e i r normal p o s i t i o n ln t h e weapon system.
5.3
Shop repair t e s t p o i n t s . External test p o i n t e shall
be provided on each WRA f o r use when the WRA i s removed from the Ve8pOn
system. The e x t e r n a l test p o i n t s , l n c o n j u n c t i o nw i t ht h eo p e r a t i o n a l
*
connectors, shall p e r m i te n d - t o - e n dq u a n t i t a t i v ec h e c k s ,c a l i b r a t i o no r
alignment, and o t h e rf u n c t i o n a lt e s t i n g
of t h e WRA. External test
p o i n t a shall also pennit, fn the w e n t of a f a i l u r e , the f a u l t i s o l a t i o n
of t h e f a u l t y S U o r c i r c u i t w i t h i n t h e
W. The a c c e p t a b l ep e r c s n t a g c
of all URA f a u l t s which ehall be i s o l a t e d t o the f a u l t y S U , o r small
group of SRAs, by ATE u t i l i z i n g external test p o i n t s s h a l l be 88 l i s t e d
l n T a b l e 105-1.
Table 105-1.
Nonambiguous SRA i s o 1 8 t i o n
RTOUPB.
1 nn*
*WUØ.
* 1 SRA
5.4
Xnternal test p a i nItnst. e r n a l
test points shall be
provided on each SRA t o p e n n i t t h e a p p l i c a t i o n
of external stimuli aud
t o permit external measurement of performance when t h e SRA is removed
from the
Internal t e s t p o i n t s shall be c o n d i t i o n e dt op r o v i d e
u n d i s t o r t e d signals t o t h e t e e t
equipment a n d s h a l l provlde t h e meam
f o r measuring i n p u t a n d output parameters t o enable c a l i b r a t i o n or
alignment of SRAS. The Internal test p o i n t s s h a l l also petmit, i n t h e
e v e n t of f a i l u r e ,t h ei s o l a t i o n
of thefaultysubassembly,
sub-=,
or
p a r t w i t h i n the SRA. The a c c e p t a b l ep e r c e n t a g e of all SRA f a u l t s which
s h a l l be ísolated t o t h e faulty subassembly,eub-SU,
or part, or a d 1
group of subaesemblles, eub-SRAs, or parts, e h a l l be 88 l i s t e d in Table
105-11.
WRA.
6. Manual f a u l it s o l a t i o n
level. Provisions and procedures
the ambiguous S M groups r e s u l t i n g from
s h a l l be developedwhichenable
BIT o r ATE I s o l a t i o n t o be further i s o l a t e d t o t h e f a u l t y
No
special support equipment shall
be r e q u i r e d and i s o l a t i o n p r o c e d u r e s
use of spare S U S from the supply system.
shallnotincludethe
SRA.
Requirement 105
daneshlink.com
6 daneshlink.com
April
1982
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
105-2
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
90%
MIL-STD-2084 (AS)
Table 105-11.
I
Fault i s o l a t i o n groups within SRA.
._
~
SUBASSEKBLY OR PART GROUP SIZE XE SRA
OF
S M FAULTS
I
GROUP S I Z E
XSOLATED
-c
r
10
GROUP SIZE
10
Automatic test equipment (ATE) compatibility. The electronic
system and each WRh and S U shall be designed t o be compatible with the
ATE designated or planned for fleet use. Compatibility requirements
snall be in accordance with MIL-STD-2076(AS).
7.
Details to be s p e c l f led. Details to be specified in the Statement
of Work shall include the following, as applicable:
8.
(R)
a.
Operational a n d support concepts an¿ requirements,
including
eE-v*irûrzsritdc u d i Lions.
b.
Lisrs of standard tools, equipment , and designated
or
planned Automatic Test Equipment.
c.
P r o j e c t e d facility, training program, s k i l l s ,
and equipment
availability
d.
manual
.
Establishment of PA approval requirements f o r
fault isolation provisions a n d procedures.
e.
Identification of t e s t attribute d a t a to be
reported
(proportion of detection, percent isolation,
ambiguity
rates, e t c . ).
f.
Delivery identification of any data items
required.
Requirement 105
6 April 1982
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
105-3
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
MIL-HDBK-20B4
9 9 9 9 7 7 0 0232'9%
AClT R
REpnIREHENT 106
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
MAINTAINABILITY INDEX
1.
Purpose. This requirement establishes c r i t e r i a f o r determining
maintainability indices of the electronic system.
2.
Referenced documents.
t o Requirement 106.
The following referenced document is applicable
STANDARDS
Military
MIL- ST& 1390
Level of Repair
3.
Definitions. Definitions applicable to Requirement 106 are ia
accordance & t h HIL-STD-1390 and Section 3 of this standard.
4.
Fixed interface ( F I ) ratios. Fixed interface (FI) ratios are a
measure of the c a p a b i l i t y to replace a single WRA or SRA without need
f o r adjustment or trimming at installation,
4.1
WRA FI ratio, The r a t i o of WRAs replaced at O-level
maintenance which do not require adjustment or trimming at installation
ír? the weawn system to the t n r e l =.aber c i km& in Lhe eiectronic
systen: shall alwaps be l e s s than 1 .O. Analytical estimates of the WRA FI
ratio s h a l l be a consideration at all d e s i g n reviews. The WRA FI ratio
is calculated as follows:
Number of WRAs not requirinE adiustment
T o t a l number of WRAs in electronic system
4.2
S R A FI r a t i o . The r a t i o of t h e numb.?r of SRAS
replaced at I-level maintenance which do not require adjustment or
trimming st installation in the WRA to the t o t a l number of S R A S in the
W R A shall always be less than 1.0.
Analyrical estimates of the Sm fI
r a t i o for each WRA shall be a consideration a t each design tevier;. The
SR4 FI r a t i o is calculated as follows:
F
'
=,
Huaber of SRAS not requirinr, adiustment
Total Number of SR+
i n t h e WRA
.
Reqrlirement 106
6 Apri 1 1982
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
MTL-STD-2084 (AS)
5.
tight replaceable assembly ( L M ) ratio.
Unless othervlse specified,
Che ratio of L W to the total number of WRAs in t h e electronic system
s h a l l n o t be less than 1.0. Analytical estimates of the LRA ratio shall
be a c o n s i d e r a t i o n a t a l l d e s i g n reviews, The LRA ratio i s calculated
as f ul:ows :
LRA r a t i o
Number of L U in e l e c t r o n i c system
Total number of WRAS in electronic system
=
6.
Q u i c k r e p l a c e a b l e assembly (QRA) ratio. The ratio of QRAS t o the
t l j t a i nuinber d f SRAs in a WRA shall n o t be less than 0.90.
Analytical
estimates of the QRA ratio for each WRA s h a l l be a consideration at all
desiRn i-eviews. The QRA ratio is calculated as follows:
"
Number of QRAs in WRA
Total number of SRAS in WRA
QRA ratio
-
7.
FI-.-r a t i o verification. When WRAS and SRAs are replaced OT substituted
d u r i n &e n g i n e e r i n g and r e l i a b i l i t y development tests, a record s h a l l be
m a i n t a i n e d f o r all c a l i b r a t i o n or alignment required to establish specified
pcrfqrma:-~c.elevels. Tnese data s h a l l be summarized to determine compliance
ox m n c o m p l i a n c e with t h e FI ratio requirements and reported in the
reliabilitv test results r e p o r t s .
8.
D e t a i l s t o be specified. Details to be s p e c i f i e d i n the
c i Lor!< shali i n c l u i e t h e following, as a p p l i c a b l e :
"W
Statement
a.
S p e c i f i c a t i o n of alternative L U r a t i o .
b.
Identification of reviews required.
c.
Deliver?, identification of any data items
required.
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
106-2
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
MIL-STD-Z084(AS)
k"PEM)IX A
APPLICATION GUIDE
10.
GENERAL
10.2
T a i l o r ei nqgu i r e m e n t s .
Each p r o v i s i o n of t h i s
s t a n d a r ds h o u l d be reviewed to d e t e r m i n et h ee x t e n t
of a p p l i c a b i l i t y .
Tailoring of requirements m y take t h e form of deletion, a d d i r i o n , or
a l t e r a t i o nt ot h es t a t e m e n t s
i n s e c t i o n s 3 , 4 , and t h ei n d i v i d u a lr e q b i r e m e n t s
i n s e c t i o n 5 to adapt the requirements t o s p e c i f i cs y s t e mc h a r a c t e r i s t i c s ,
procuring a c t i v i t yo p t i o n s ,c o n t r a c t u a ls t r u c t u r e ,
or a c q u i s i c i o np h a s e .
The t a i l o r e dr e q u i r e m e n t sa r es p e c i f i e di nt h ec o n t r a c t u a lp r o v i s i o n st o
i n c l u d ei n p u t t o t h e starelnent of work, contract àata requirement l i s t
(CDRL), a n do t h e rc o n c r a c t u a l
means. The depth and d e t a i l of t h em a i n t a i n a b i l i t y
d e s i g n e f f o r t w i l l be d e f i n e d i n appropriate c o n t r a c t u a l and o t h e r
programdocumentation.
10.3
User. T'ne user of this
appendix
may i n c l u d e t h e
p r o c u r i n g a c t i v i t y , Governmentin-house
a c t i v i t y , prime c o n t r a c t o r , o r
C ~ b ~ n ~ l T f ~ühû
~ t h-ishcs
cz
LU impose requirements for maintainabil it? of
a v i o n i c anó e l e c t r o n i c s y s t e m s and equipment upon his s u p p l i e r ( s ) .
20, REFERENCED DOCUMENTS ( n oat p p l i c a b l e )
30.
DEFIKITIONS ( n o t a p p l i c a b l e )
40.
GENERAL REQUIREMEKTS
40.1
R e q u i r e ms e nl et sc t i o n .
The c o n s i d e r a t i o n s prcscnted
h e r e i n are intended t o provideguidance and r a t i o n a l e f o r s e l e c t i o n of
requirements. Once a p p r o p r i a t er e q u i r e m e n t s have been s e l e c t e d , Che
requirementsthemselves can be t a i l o r e d . The timing and d e p t h of each
requirement, as well as a c t i o n t o be taken based on requirement outcome,
are l a r g e l yd e p e n d e n t on i n d i v i d u a le x p e r i e n c e and program requirements.
F o r these r e a s o n s , hard and f a s t r u l e s are n o ts t a t e d .
40.2
A p p l i c a t i o n matrix f o r program phases. T a b l e 11-1
h e r e i n provides generci guidance, ln summary form, of which requirements
t o i n c l u d e i n an RFP i n order to emphasizemaintainability by design.
T h i s table can beused
t oi n i t i a l l yi d e n t i f yr e q u i r e m e n t st h e nt h e
user
c a n r e f e r to t h ep a r t i c u l a rr e q u i r e m e n t
and determine if i t i s npl)rolwi.?te
f o r h i s program. The use of the matrix is t o be considered 3s optional
guidance only and is not t o be construed as covering a l l procurement
s i t u a t i o n s . The p r o v i s i o n s of a p p l i c a b l er e g u l a t i o n s must also h(,
followed.
A- 1
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
10. I
Scope.
This
appendix
provides
notes f o r the
guidance
of t h e p r o c u r i n g a c t i v i t y
i n g e n e r a t i n gt h ec o n t r a c t u a lr e q u i r e m e n t s
for
the m a i n t a i n a b i l i t yf e a t u r e sd e s i g n e d
and b u i l t i n t o a v i o n i c and e l e c t r o n i c
systems and equipment.
7799970 0212771 3 T 4
MIL-HDBK-20B4
EIIL-Sm-2084 (As)
TABLE A - I .
Requirement Title
Application matrix.
Concept
.
Valid
FSED
Prod
G(1)
G(1)
G(1)
G(1) (2)
G(1.)
C
G(2)
G
C
101 M a i n t a i n a b i l i t y program
S
102 Failure mode and effects
analysis
S
103 Physical design
S
104 B u i l t - i n - t e s t
s
.G
G
C
105 Test p o i n t s
S
G
c
C
106 M a i n t a i n a b i l i t y i n d e x
S
G(2)
G
C
-
Code D e f i n i t i o n s
S
- S e l e c t i v e l y applicable
-
Generallyapplicable
G e n e r a l l y a p p l i c a b l e t o designchanges only
( I ) - MIL-STD-2084 is not p r i m a r y implementingdocument
( 2 ) - Depends on p h y s i c a l complexity of system being procured, its
packaging, and maintenancepolicy.
G
C
4û. 3
hequirement. p r i o r i t i z a t i o n . The problem of prioritizing
requirements cannot be solved unless v a r i a b l e s like system complexity,
availability of f u n d s , schedule, maintenance c o n c e p t ,l o g i s t i cs u p p o r t
requirements, e t c e t e r a are known. The m a i n t a i n a b i l i t y program (Requirement
101) should always be consideredforselection;however,
individual
m a i n t a i n a b i l i t y program tasks from MIL-STD-470 may be c i t e d in t h e
c o n t r a c t wichout requiringRequirement101.
50.
DETAIL REQUIREXENTS
-
50.1
Requirement 101 M a i n t a i n a b i l i t y Program. The
elements of the m i n t a i n a b i l i t y program i d e n t i f i e d ln Requirement 101
are considered to bethe minimum f o r effectivelyimplenrenting a m a i n t a i n a b i l i t y
by design approach. The tasks which are included e s t a b l i s h the framework
f o r m a i n t a i n a b i l i t y b y design a n d such tasks should be levied a t the
equipment level or at the systcm l e v e l whichever i s most a p p r o p r i a t e .
Otherelements of a m a i n t a i n a b i l i t y progrm must be selected from MILSTD-470 t o meet t h e overall m a i n t a i n a b i l i t y needs. I d e n t i f y i n g and
q u a n t i f y i n g program needs must be accmnplished prior t o release of an
RFP f o r t h e a p p r o p r i a t e acquisition phase so that maintainability program
tasks commensurate withtheneeds
may be included in the RFP.
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
A- 2
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
MIL-HDBK-2084
9 9 9 4 9 7 0 0222792 230
prttSTD-2084 (As)
50.2
FMEA is
RcquireaPcat 102
- Failure Mode and Effects Analysis (FKEA).
a powerful tool in the development of fault detection and
Isolation d e ~ f g a rat 111 hardware lcvclr: The ef fectiveneos and eff icícncy
of fault detection and i u o l a t i o a are critical drivers of maintainability
s t organizetimal, shop, and depot levels of maintenance. Through the
use of an PHEA, potential design weaknesses which can impact s a f e t y and
reliability mayd e o be îdentif id.
An
Depth a n d ncope of the FHEA l e dependent on the maintainability requirements
levied in the RPP a d the ccrmplaxitp and nature of the item undergoing
procurement. Care muat be takra when epecifyíng maintainability requirements
to Indicate whether t h e y relate to org.nfzationa1 maintenance, shop
level maintenance or depor level maintenance or to aome combination of
these a8 such requirer~entoimpact fntarptetstjons of what i19required
f o r the FMEA requirement.
-
50.3
Requirement 103 Physical Design. The physical
design of electronic ryrtc~loi8 directed to incorporating features which
w i l l minimize tutfnterrcmcc downthe, c o s t , c o m p l e x i t y , and personnel
requirements, Design criteria muat be developed to assist the maintainability
analyst l n the ßelaction of 1lralnt6l~bllityquantitative design features
which enable coat e f f e c t i v e mainteaaacc eupport throughout the deployed
life of t h e s y ~ t e m .
The phyalcrl design muat consider -ch maintenance t a s k and provide for
logical and aaqoentirl functions with miaimrna numbers of personnel and
maintenance ttpecialftias, The design should permit p h y ~ i c a land functfonal
acce8s to 'any active item upon opening or remova of access entries
without nerd for prior r e w v a l or movement of other items. All repair
part items having the same part nmber shall be physically and functionally
interchangeable without modification or adjustment of the item or the
s y s t e m l n which they are used. The performance of a l l maintenance tasks
at organizational and intermediate levelmaintenance should be accomplished
without need for special tools and w i t h a minimum of malntensnce tools,
accessories and equipment.
-
50.4
Requíremmt 104
Built-In-Test (BIT). The maintainability
requirements of electronic systems ~ z e , in most caEes, highly dependent
un t h e adequacy oad eff1cAency of t e s t system design. T e s t s y s t e m
cannot be considered aa an afterthought, but must be considered a8 an
Integral patt of the design if ease of nutintenance is t o be Increased
and maintenance downtime decreased.
BIT capability incorporated I n t o the s y s t e m design serves two basic
functionu. First, to provide a fault detection function, and second, ta
provide i r o l a t i o n t o the defectfve item or function. The level of BIT
that will be required t o i B O l 4 t e defective ítema or functions is
A
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
A-3
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
d i r e c t l y r e l a t e d t o thenean-time-to-repair
(HTTR) requirement for t h e
system. Rapid and easy fault l o c a l i z a t i o n and repair d i c t a t e that t h e
fault be diagnosed by f u n c t i o n and t h a t t h e f u n c t i o n be implemented by
small s e t of replaceable m d u l e s .K o d u l a r i z a t i o np e r m i t s
faster f a u l t
i s o l a t i o n ,c o r r e c t i o n , , a n dv e r i f i c a t i o n .
8
is Important t o a s s u r e e f f e c t i v e BIT design.
Designingfortestability
The BIT designshould be keptsimple and " s t a t e - o f - t h e - a r t " d e s i g n s t h a t
are unprovenshouldbeavoided.
BIT must be r e l i a b l e and a f a i l u r e in
t h e B I T c i r c u i t r y or devicesshouldnotaffectsystemperformance.
The
t y p e of c i r c u i t r y u s e d in BIT should be, where f e a s i b l e , ofthe same
typesusedintheelectronicsystemdesign
to minimize t h e number of
d i f f e r e n t p a r t types w e d .
Valuable and necessary inputs
following:
0
to BIT design are o b t a i n e d from among t h e
R e l i a b i l i t yp r e d i c t i o n s
o F a i l u r e mode and e f f e c t s analysis
0
M a i n t a i n a b i l i t ya n a l y s i s
o fIuman f a c t o r s studies which recommend skill levels and
numbers of personnelrequired.
-
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
50.5
Requirement 105
Test P o i n t s . Test p o i n t s are a
considerationinbothelectronicsystemdesign
and BIT design since
Automatic Test Equipment (ATE) a c c e s s i b i l i t y must be provided t o both
i n i c r a t e BLT o p e r a t i o n and t o test the system. BIT and ATE t e s t p o i n t s
must becompatible a n d harmonlzlng. BIT and ATE r e q u i r ee v a l u a t i n g the
r e l a t i v ea d v a n t a g e s of each method. Allocation of r e s p e c t i v e test
f u n c t i o n s w i l l be t h e result of t r a d e - o f f c o n s i d e r a t i o n s s i n c e n e i t h e r
test method can f u l l yr e p l a c e the o t h e r . From the t o t a l l i f e c y c l e cost
p o i n t of view, BIT permitsconsiderable cost savingsthroughthereduction
of maintenance a n h o u r s when properly applied and d e s i g n e d t o i n t e r f a c e
w i t h ATE.
Enough test p o i n t s and connectorsshould be providedtopermitmonftoring
o r i n j e c t i o n of i n p u t eignals i n t o shop replaceableassemblies ( S M ),
t h em o n i t o r i n go ri n j e c t i o n
of output signals t o S U ' S , and t h e m o n i t o r i n g
o r I n j e c t i o n of c o n t r o l signals. Primaryconsiderationindetermining
numberand
l o c a t i o n of test p o i n t s is thedegree of r e q u i r e d f a u l t
iSOl8tiOn.
AL1 f u n c t i o n s of each next lowerassembly should be checked
o u t . All available p i n s on a test connector should be u t i l i z e d i n s t e a d
of relpfag on manual probing of i n t e r n a l t e s t terminals.
In t h e d e s i g n of e l e c t r o n i c s y s t e m s , it is o f t e n n o t p o s s i b l e t o l o c a t e
a l l faults t o a s i n g l e item with B I T ar at the a v a i l a b l e test p o i n t s
w i t h ATE. Thus, f a u l t irrolation may a l s or e q u i r e a manual approach. A
p r o c e d u r e u t i l i z i n g a t a b u l a ra p p r o a c ht of a u l tf i n d i n g
can be used t o
localize f a u l t sw i t h i n a small set of r e p l a c e a b l e items. This procedure
A-4
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT
MIL-STD-2084 (AS)
l a b a e d upon a tabular presentatiofï of 'syetem behavior under different
input conditione or mode6 of operation. Each replaceable item can be
i d e n t i f l e d in the coltmrns of a matrix and each test performed i d e n t i f i e d
in the rows. The entries i n each position of the matrix will then
define the items involved in a given t e s t . An "X" i n the box means that
the itfa could bec the cause of failure in a particular t e s t , Teet f o r
t h i s manual procedure would not be confined to the usual BIT or ATE, but
may encompase a l l modes of operation including normal, B I T , calibration,
ATE, and eelf-teer. There could be several testa sesociatedvith a
given set of input conditions where each t e s t repteeents a row in the
matrix. Each teer. should be consideredindependent
w i t h respect t o the
order i n which they are performed and the outcome .of each t e s t would be
a pass OY f a i l . If one test f a i l s , then a l l item ' X r ' & in that tow
vould be f a u l t candidates and further testing would be necessary.
b n u a l procedures are simple. If a test f a i l s ,v e r t i c a ll i n e sa r e
drawn
through a l l coluums that do not have any "X" entries. The '%''B in theae
columns are eliminated f r m further consideration i n any subsequent
t e s t . ff a test passes, B horizontal line I s drawn through the t e s t
row. Wherever an "X" appears i n that row, that column is then eliminated
by drawing 8 v e r t i c a l l i n e through that column. Thus, faultambiguities
can be resolved manually throughthe procees of elimination.
-
50.6
9 u l r e m e n t 106
Maintafnabllitv Index. A measure
of hou well a particular electronic system design meet8 specific maintainability
requirements can be assessed through the vsrious maintainability indicee.
The design can be asses8ed through the W,QRA, and FI r a t i o s for WRAs
and SRAe to prctvid~,in2!izar:sr, of the ease or' remove a n d replace and the
influence on numbers of personnel a n d maintenance manhours. The lower
these ratios are, the more d i f f i c u l t the maintensnce tasks w i l l become
a n d , in general, more personnel and more maintenance manhours w i l l be
required.
--`,``,,,````````,`,,``,``,-`-`,,`,,`,`,,`---
A-5
daneshlink.com
daneshlink.com
Provided by IHS
No reproduction or networking permitted without license from IHS
Licensed by www.sepana.ir
Sale for only by www.sepana.ir, 05/25/2014 09:11:23 MDT