COSYSMO 2.0 Workshop Summary
(held Monday, March 17th 2008)
USC CSSE Annual Research Review
March 18, 2008
Jared Fortune
Agenda
• Topics covered
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Overview of COSYSMO
Summary of COSYSMO 2.0 improvements
Reuse (overview)
Integration between SWE and SysE
Risk modeling (overview)
Assumption of linearity in cost drivers
Modeling organizational factors in space systems
Best practice guidance
Cost drivers vs. scale factors
Cost driver impact survey results
Recursive levels of design
• Joint meeting with SoS cost estimation group
2
Attendees (18)
•
Jeff Allen (Lockheed Martin)*
•
Cynthia Nikolai (Notre Dame)
•
Barry Boehm (USC)
•
Elizabeth O’Donnell (Boeing)
•
Jim Cain (BAE)
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Garry Roedler (Lockheed Martin)
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Jared Fortune (USC)
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Rick Selby (Northrop Grumman)
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Gary Hafen (Lockheed Martin)
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Howard Schimmdler (Lockheed Martin)*
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JoAnn Lane (USC)
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Ricardo Valerdi (MIT)*
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Dan Ligett (Softstar)
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Gan Wang (BAE)
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Miles Nesman (Boeing)
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Darryl Webb (Aerospace)
•
Ali Nikolai (SAIC)
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Marilee Wheaton (Aerospace)
* Via Phone
3
Recommended COSYSMO 2.0 Improvements
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Reuse
Integration of SwE & SysE estimation
Assumption of linearity in COSYSMO cost drivers
Effect of cost drivers and scale factors
Number of recursive levels of design
Risk modeling
Establishing best practice guidance
Consideration of SoS scope in COSYSMO
Estimation in Operation & Maintenance Phase
Requirements volatility
4
Reuse
• What is the effect of reuse in estimating systems
engineering size/effort?
• On-going efforts by Valerdi, BAE, and Lockheed
– Definitions: New, Modified, Adopted, Deleted, Managed
• Incorporate reuse into COSYSMO
– Collect data to obtain statistical significance
– Opportunistic vs. systematic reuse
• Select exemplar program to support reuse definitions
• Assist in development of best practice guide
– Ensure consistency across organizations
5
SWE and SysE Integration
• What is the overlap between COCOMO II and
COSYSMO?
– Not model integration, scope overlap
• WBS element ownership exercise
– Attempt at capturing SysE effort
– System, Software, Supportability, PEM; in COSYSMO or not
• COSYSMO data covers a broader scope that textbook
definition of “systems engineering”
• Sometimes to distinguish who is responsible (funds)
specific WBS elements
– Areas of overlap
6
Risk Modeling
• How can risk associated with the COSYSMO estimate
be quantified?
• On-going effort at Lockheed with COSYSMOR
• Provide Low, Likely, High estimates
• Presented one methodology, will be undergoing peer
review
• Illustrated need for best practice guide to reduce
unnecessary (incorrect) risk assessments
• To be incorporated into COSYSMO 2.0 baseline (Valerdi
book)
7
Linearity Across the Life Cycle
• Do all cost drivers have the same impact across the
lifecycle?
• Values of some drivers may not exist in all phases
• Single “step” between driver values can be very large
– Raised possibility of weighting drivers
• Subgroup will discuss further, report results at next
meeting
8
Modeling Organizational Factors
• What are the quantifiable organizational issues that drive
cost?
• Help explain why a predicted cost is reasonable
• Highlight potential biases in estimates
• Presented data from STS and ISS
• Results provided strong indicators that program
complexity and organizational structure are major cost
drivers
9
Best Practice Guidance
• How can misuse of the COSYSMO cost drivers be
avoided?
• Correct assessment of values for cost drivers
• Limit underestimation
• Reuse
• Ensure consistency across programs
• Created Committee
• Will present results at next meeting
10
Cost vs. Size Driver Correlation
• Can some of the cost drivers become scale factors in the
cost estimating relationship calibrated by the new data
set?
• Presented results of October 2007 survey
• Distributed new survey
• Result: “it depends”
11
Recursive Levels
• How can the integration complexity of system elements
one layer below the system-of-interest be
operationalized?
• Generated a lot of discussion, but a long way to go on
guidance
• Attempt to incorporate in best practice guide
12
Prioritization
Criteria
R
eu
s
e
SW
E
&
S
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ne y s E
ar
ity
C
os
tD
ri
R
ec ver
s
,L
&
e
v,
Sc
R
is
o
k
f D ale
M
Fa
es
od
B
i
es
gn cto
e
t P li n
rs
g
r
a
So
ct
S
i
in ce
G
C
O
u
O
&
SY ide
M
SM
R
O
eq
.V
ol
at
ili
ty
Improvements
Availability of Data
Impact on TOC
Frequency of Use
Compatible with Models
Address Trends
Factor Interactions
Priority
H
M
H
H
H
L
L
M+
L
H
H
L
L
H
M
L
H
H
L
L
H
M
L
H
H
M
M
L
M
H
H
M
H
L
M
H
M+
L
M
L
M
M
L
L+
L
L
13