Modeling, Simulation and Analysis
DSES 6620
FINAL PROJECT:
Modeling and Simulation of Jet Engine Components
Repair Unit
Jacek Spychalski
12/05/02
Prof. Ernesto Gutierrez-Miravete
1
Table of Contents:
1. Introduction
3
2. Main Objectives
3
3. Process Description
3
3.a) Entities
3
3.b) Locations
4
3.c) Arrivals
6
3.d) Process and Routing
7
4. Results of Simulation
14
2
1. Introduction
Conceptual Process Cell for Jet Engine components at Pratt & Whitney Aftermarket Services Repair Business
Unit was the subject of this project. Previous work experience in this area have given an idea about hypothetical unit
in which three real jet engine parts will be repaired. Although described process cell does not exist, model was based
on real overhaul facility that processes wide variety of different components.
ProModel software was used to build a model, which will allow to simulate a workflow in this conceptual
repair station process cell. Results obtained from simulation will allow conducting analysis based on which further
conclusions will be made.
2. Main Objectives
Purpose of this simulation and analysis is to demonstrate the modeling capability and optimize the workflow
to obtain maximum throughput in minimum time. Best utilization of all the machines/workstations is the key to
successful simulation. Assuming that process times for certain machines that repair appropriate component are
specified and all the machines have constant rate of failure depending on the type of piece of equipment, machine
capacities can be modified.
3. Process Description
3.a)
Entities
Three components from PW4000-112” (PW4098) will be used in this model:
1. High Pressure Compressor 5th Stage Disk, P/N 56H506 – Component_1:
2. High Pressure Compressor Front Hub, P/N 51H572 – Component_2:
3
3. High Pressure Compressor 15th Stage Disk, P/N 56H005 – Component_3:
3.b)
-
Locations
Model consists of 12 locations:
5 fully automated machines (CMM, VTL1, Surface Treat, VTL2, Grinder)
3 inspection locations (Receive_In, Visual Inspection, Final Inspection)
2 non-destructive inspections (FPI, Local_FPI)
1 Cleaning
1 Blending Booth
Schematics:
4
RECEIVE IN
CLEAN
CMM
FPI
VISUAL
INSPECTION
BLENDING
VTL 1
FINAL
INSPECTION
GRINDER
SURFACE
TREAT
VTL 2
LOCAL FPI
Above schematics shows all possible routing that any of the three components can be processed through.
Colors of the arrows correspond to the following routings:
Component 1, 2 & 3
Component 2
Component 3
Component 1 & 3
Component 1
Component 1 & 2
Sequencing in operations for all three components was a deciding factor in laying out the cell.
3.c)
Arrivals
Arrival and service completion events for three types of parts will be defined by discrete distribution of random
variables specific to appropriate component.
5
Arrivals distribution data was generated using Stat Fit program. Ten parts of three Entities (Component1, 2,
3) were tracked down at Receive In location in Pratt and Whitney facility. Following data was obtained from
observation:
Occurance
1
2
3
4
5
6
7
8
9
10
Arrival Intervals (time between arrivals in min)
Component 1
Component 2
Component 3
360
900
1260
240
1200
720
300
900
840
360
720
1440
360
840
840
420
1080
540
360
1200
420
720
660
960
360
780
1320
300
960
1140
Autofit option was used to generate fitted distributions:
3. d)
Processing and Routing:
As previously stated Process Cell in this repair station consists of 12 elements which layout is presented on
previous pages. Although all of the machines (elements) are used during the process of overhaul, my three entities
utilize the machines in a three different patterns of routing. Process time for every machine and every component is
6
defined by distributions generated in Stat Fit. Real time data collected from the observations of the actual processes
was provided to the program to generate the distributions. Next based on the highest rank of any given distribution
proper distribution function was selected and applied to the correct model processes.
Starting in from Receive In location below are the results of the observation along with selected distributions:
(For more information regarding distributions please look into Process Times.xls in Process Data folder)
Process Times at Receive In
Occurances Component 1 Component 2 Component 3
1
9
11
20
2
15
15
25
3
14
15
22
4
16
14
21
5
8
20
20
6
12
22
20
7
18
18
23
8
12
17
19
9
15
14
21
10
13
15
25
_____________________________________________________________________________________________
Process Times at Clean
Occurances Component 1 Component 2 Component 3
1
30
35
21
2
35
39
20
3
35
38
28
4
36
40
22
5
38
41
25
6
35
40
25
7
34
38
24
7
_____________________________________________________________________________________________
Process Times at FPI
Occurances Component 1 Component 2 Component 3
1
40
35
43
2
39
33
44
3
38
33
44
4
40
38
42
5
38
35
41
6
38
34
44
7
35
35
45
8
38
33
43
9
39
35
43
10
37
33
42
8
Process Times at CMM
Occurances Component 1 Component 2 Component 3
1
31
36
41
2
30
36
40
3
30
35
40
4
30
36
40
5
32
32
41
6
35
35
42
7
36
38
41
8
30
35
41
9
35
35
40
10
32
32
40
______________________________________________________________________________________________
Process Times at Visual Insp.
Occurances Component 1 Component 2 Component 3
1
62
66
70
2
65
65
75
3
68
68
73
4
60
66
68
5
68
57
75
6
68
55
71
7
65
63
69
8
60
60
64
9
62
61
68
10
58
68
75
9
Process Times at Blending (min)
Occurances Component 1 Component 2 Component 3
1
56
N/A
35
2
55
N/A
38
3
54
N/A
34
4
55
N/A
37
5
51
N/A
37
6
55
N/A
38
7
58
N/A
35
8
54
N/A
40
9
57
N/A
38
10
55
N/A
34
_______________________________________________________________________________________
Process Times at VTL1 (min)
Occurances Component 1 Component 2 Component 3
1
120
N/A
155
2
130
N/A
150
3
130
N/A
158
4
125
N/A
156
5
140
N/A
165
6
120
N/A
150
7
120
N/A
140
8
125
N/A
145
9
135
N/A
140
10
120
N/A
140
10
Process Times at Local FPI (min)
Occurances Component 1 Component 2 Component 3
1
35
N/A
37
2
35
N/A
34
3
38
N/A
37
4
34
N/A
37
5
37
N/A
35
6
37
N/A
38
7
35
N/A
35
8
35
N/A
35
9
38
N/A
36
10
34
N/A
34
___________________________________________________________________________________________
Process Times at Surface Treat (min)
Occurances Component 1 Component 2 Component 3
1
165
N/A
170
2
150
N/A
160
3
155
N/A
165
4
168
N/A
150
5
160
N/A
150
6
170
N/A
155
7
155
N/A
150
8
165
N/A
165
9
160
N/A
170
10
160
N/A
155
11
Process Times at VTL2 (min)
Occurances Component 1 Component 2 Component 3
1
150
145
N/A
2
140
150
N/A
3
145
142
N/A
4
135
140
N/A
5
150
150
N/A
6
155
155
N/A
7
150
158
N/A
8
145
140
N/A
9
135
140
N/A
10
155
145
N/A
_____________________________________________________________________________________________
Process Times at Grinder (min)
Occurances Component 1 Component 2 Component 3
1
N/A
N/A
180
2
N/A
N/A
165
3
N/A
N/A
180
4
N/A
N/A
170
5
N/A
N/A
175
6
N/A
N/A
165
7
N/A
N/A
165
8
N/A
N/A
170
9
N/A
N/A
185
10
N/A
N/A
160
12
Process Times at Final Insp (min)
Occurances Component 1 Component 2 Component 3
1
40
50
34
2
35
48
35
3
45
55
36
4
40
51
35
5
41
49
41
6
48
48
39
7
47
45
41
8
45
51
40
9
40
56
38
10
41
47
37
Summarizing all the distribution functions for all the processes:
1. Receive In – initial station for all the components that can accommodate infinite number of entities
Component 1: Weibull (8, 2.46, 6.47)
Component 2: Uniform (11, 22)
Component 3: Triangular (18, 26.8, 19.8)
2. Clean – clean line; common to all three components with the following process time distributions:\
Component 1: Pearson 5 (30, 34.1, 176)
Component 2: Triangular (34, 41.8, 41)
Component 3: Uniform (20, 28)
3. FPI – Full Fluorescent Penetrant Inspection
Component 1: Triangular (34, 40.7, 40)
Component 2: Triangular (32, 39, 32.7)
Component 3: Triangular (40, 45.6, 43.9)
4. CMM – Computer Measurement Machine allows for dimensional inspection
Component 1: Triangular (29, 37.8, 29.9)
Component 2: Triangular (31, 39, 35)
Component 3: Triangular (39, 42.4, 40.4)
5. Visual Inspection – parts are visually inspected and directed to proper machines for process
Component 1: Weibull (58, 2.1, 7.04)
Component 2: Weibull (55, 2.72, 9.85)
Component 3: Lognormal (64, 1.95, 0.4)
13
6. Blending – all of the parts required operation
Component 1: Beta (51, 58, 6.99, 4.8)
Component 3: Uniform (34, 40)
7. VTL 1 – Machine used exclusively for pre-machining operation
Component 1: Triangular: (119, 144, 119)
Component 3: Triangular: (139, 171, 139)
8. Local F.P.I. – Local Fluorescent Penetrant Inspection assures no surface damage after preMachining
Component 1: Erlang (34, 1, 1.8)
Component 3: Gamma (34, 1, 1.8)
9. Surface Treat – applies coating to surfaces previously pre-machined
Component 1: Triangular (149, 175, 159)
Component 3: Triangular (149, 177, 149)
10. VTL 2 – finish machine of Component 1 and machine to size of Component 2
Component 1: Uniform (135, 155)
Component 2: Triangular (139, 162, 139)
11. Grinder -finish grind
Component 3: Uniform (160, 185)
12. Final Inspection
Component 1: Triangular (34, 50.9, 40.8)
Component 2: Triangular (44, 58.4, 48.3)
Component 3: Exponential (34, 3.6)
As it can be noticed from above description three components will utilize (share) same machinery for certain
operations. However some processes will remain unique and specific for appropriate type of hardware therefore
proper man-hour and capital machinery planning will be crucial to the simulation. Time reduction and flawless
procedures within this conceptual cell will be the goal for successful simulation.
Repair cell will accommodate 5 machines, 5 manual workbenches and 3 inspection areas. Operators will work
8 hours in a 3-shift pattern. Operation on particular machine or workbench will take same amount of time depending
on the type of hardware as specified in previous paragraphs. The operator will be responsible for loading and
unloading parts, providing perishable tools to each of the machines, and clearing the technical problems caused by
machines.
4. Results of Simulation
Results from model simulation show high percentage of utilization most of the workstations. See data below for outputuj
General Report
Output from \\Vaio\SharedDocs\Documents\Simulation Modeling & Analysis DSES6620\Project\Project.mod
Date: Dec/19/2002 Time: 04:34:21 PM
-------------------------------------------------------------------------------Scenario
: Normal Run
14
Replication : 1 of 1
Simulation Time : 720 hr
--------------------------------------------------------------------------------
LOCATIONS
Average
Location
Scheduled
Total Minutes Average Maximum Current
Name
Hours Capacity Entries Per Entry Contents Contents Contents % Util
------------- --------- -------- ------- ----------- -------- -------- -------- -----Surface treat
720
1 200 198.680280 0.919816
1
1 91.98
Grinder
720
1
64 136.890547 0.202801
1
0 20.28
VTL 1
720
1 203 197.015611 0.925791
1
1 92.58
CMM
720
1 248 158.588940 0.910418
1
1 91.04
Visual Insp
720
1 247 157.260061 0.899149
1
1 89.91
Receive In
720 999999 331 4303.445728 32.9732
81
81 0.00
Blending
720
2 246 333.891041 1.90132
2
2 95.07
FPI
720
1 249 158.250972 0.912141
1
1 91.21
Clean
720
1 250 157.380508 0.910767
1
1 91.08
Local FPI
720
2 202 403.405104 1.88629
2
2 94.31
VTL 2
720
1 176 150.413108 0.612794
1
1 61.28
Final Insp
720
1 239 39.859088 0.220517
1
0 22.05
LOCATION STATES BY PERCENTAGE (Multiple Capacity)
%
|
Location Scheduled % Partially % | %
Name
Hours Empty Occupied Full | Down
---------- --------- ----- --------- ----- | ---Receive In
720 0.42 99.58 0.00 | 0.00
Blending
720 0.54
8.79 90.67 | 0.00
Local FPI
720 1.12
9.14 89.75 | 0.00
LOCATION STATES BY PERCENTAGE (Single Capacity/Tanks)
Location
Scheduled
% % %
%
% %
Name
Hours Operation Setup Idle Waiting Blocked Down
------------- --------- --------- ----- ----- ------- ------- ---Surface treat
720 73.84 0.00 8.01 0.00 18.15 0.00
Grinder
720
19.61 0.00 79.72 0.00 0.67 0.00
VTL 1
720
63.41 0.00 7.42 0.00 29.17 0.00
CMM
720
21.25 0.00 8.95 0.00 69.80 0.00
Visual Insp
720
1.00 0.00 10.08 0.00 88.92 0.00
FPI
720
22.24 0.00 8.79 0.00 68.97 0.00
Clean
720
7.39 0.00 8.92 0.00 83.69 0.00
VTL 2
720
59.21 0.00 38.72 0.00 2.07 0.00
Final Insp
720 22.05 0.00 77.95 0.00 0.00 0.00
FAILED ARRIVALS
15
Entity
Location Total
Name
Name
Failed
----------- ---------- -----Component 1 Receive In
0
Component 2 Receive In
0
Component 3 Receive In
0
ENTITY ACTIVITY
Average Average Average Average Average
Current Minutes Minutes Minutes Minutes Minutes
Entity
Total Quantity
In In Move Wait For
In
Name
Exits In System
System
Logic Res, etc. Operation Blocked
----------- ----- --------- ----------- ---------- --------- ---------- ----------Component 1 134
50 6186.389888 150.000000 0.000000 589.349045 5447.040843
Component 2 41
21 5355.897488 105.000000 0.000000 355.938902 4894.958585
Component 3 64
21 6225.445453 150.000000 0.000000 765.024234 5310.421219
ENTITY STATES BY PERCENTAGE
%
%
Entity
In Move Wait For
%
%
Name
Logic Res, etc. In Operation Blocked
----------- ------- --------- ------------ ------Component 1 2.42
0.00
9.53 88.05
Component 2 1.96
0.00
6.65 91.39
Component 3 2.41
0.00
12.29 85.30
VARIABLES
Average
Variable Total Minutes Minimum Maximum Current Average
Name Changes Per Change Value Value Value Value
-------- ------- ---------- ------- ------- ------- ------WIPC1
318 135.595434
0
50
50 24.8949
WIPC2
102 422.672078
0
24
20 7.89854
WIPC3
149 285.579503
0
23
21 11.2231
WIPT
569 75.780928
0
91
91 44.0165
16