Pipe spool fabrication is major component of construction operations on large industrial projects. The nature of spooling is relatively short term involving complex construction process and riddled with uncertainty due to the intrinsic unique nature of its outputs and the numerous factors affecting its activities. With this in mind, it is important for all stakeholders to have a good grasp of the performance of pipe fabrication shops and their ability to meet the site pipe installation schedules.

1. Master Title
Click to edit Master subtitle style
Computer Simulation
of Pipe Fabrication
Zuhair Haddad
Chief Information Officer
CCC
Ramzi Labban
Manager, Computer Modeling & Simulation
CCC

2. Agenda
• Introduction
• Simulation at CCC
• Pipe Spool Fabrication
• Discrete Event Simulation Model
• Benchmarking
• Case Study

3. Simulation at CCC
• Computer Based Modeling and Simulation has been
in use at CCC since late 2005
• Main uses include:
• Low Level Resource Planning
• Performance Improvement
• Process Optimization
• Schedule Validation
• Look Ahead Scheduling
• Assessing Direct and Indirect Impact of Changes (Delay
and Disruption, lost productivity & rework)
• Quantification and Justification of Claims

4. Simulation at CCC
• Material Forward Planning (piping)
• Earthworks
• Asphalt Paving
• Pipe Fabrication and Erection
• Pipeline Construction
• Building Finishing Activities

5. • Pipe spool fabrication
– A major component of construction operations on
large industrial projects
– Relatively short term, complex construction process
– Riddled with uncertainty due to the intrinsic unique
nature of its outputs and the numerous factors
affecting its activities
– Directly affects pipe installation
• Important for all stakeholders to have a good grasp
of the performance of pipe fabrication shops and
their ability to meet the site pipe installation
schedules
Pipe Spool Fabrication

6. Pipe Spool Fabrication
• Fabrication Managers or Subcontractors want to
“optimize” their operations:
– fabricate large bore/heavy spools early in the process
– fabricate even if out of sequence
• For in-house shops: this keeps manpower busy
• For subcontractors: this allows them to earn more
cash up front (usually paid by tonnage)
• Fabricating out of sequence material required for
critical activities leads to delays and disruptions in
the fabrication and site installation process

7. Example of effect of out of sequence fabrication
Project Progress– Week 53 (1 of 8)
All rights reserved to CCC

8. Example of effect of out of sequence fabrication
Project Progress– Week 54 (2 of 8)
All rights reserved to CCC

9. Example of effect of out of sequence fabrication
Project Progress– Week 55 (3 of 8)
All rights reserved to CCC

10. Example of effect of out of sequence fabrication
Project Progress– Week 56 (4 of 8)
All rights reserved to CCC

11. Example of effect of out of sequence fabrication
Project Progress– Week 57 (5 of 8)
All rights reserved to CCC

12. Example of effect of out of sequence fabrication
Lessons Learned – Week 58 (6 of 8)
All rights reserved to CCC

13. Example of effect of out of sequence fabrication
Project Progress– Week 59 (7 of 8)
All rights reserved to CCC

14. Example of effect of out of sequence fabrication
Project Progress– Week 60 (8 of 8)
All rights reserved to CCC

15. Pipe Spool Fabrication
• Fabrication needs to meet site installation
schedule
• Site sequences should drive fabrication
sequences (i.e. Priority areas, levels [bottom to
up], etc…)
• A balance between fabrication shop productivity
and cohesion to site installation schedules and
priorities needs to exist:
– Fabrication of spools adheres to site installation
schedule
– Fabrication shop manpower idle is kept to a minimum
– Critical material is available for critical activities

16. Pipe Spool Fabrication
• Pipe construction managers need to be able to
quickly come up with alternate
fabrication/installation plans based on changing site
conditions:
– Major piece(s) of equipment delayed or damaged
– Material shortage(s)
– Redesign of a system or structure

17. • Forecasting pipe spool fabrication activity
completion and optimizing resource allocation and
utilization are complicated by two main factors:
– very large number of spools
– diverse characteristics and resource requirements for each
spool
• A complex task well suited to computer modeling
and simulation
Pipe Spool Fabrication

18. How can the Pipe Spool Fabrication Simulator help?
• The pipe spool fabrication simulator provides stakeholders and end users
with a tool to proactively perform schedule validation and low level
resource planning on pipe fabrication activities on large industrial projects
• The simulation model can be run during the different phases of a project:
– Ahead of the project in predictive mode
– During execution to aid in optimization and forecasting
– Retrospectively for change impact assessment and/or lessons-learned analysis
• It helps answer questions such as:
– Will we be able to finish the fabrication activities on time with the proposed
resources?
– Which specific resources are bottlenecks?
– Which resources are under-utilized?
– How is actual crew productivity compared to planned and forecast
productivities

19. Simulation Model
• Abstraction of the real world pipe spool fabrication
process into a simulation model representing the
operations of a pipe spool fabrication shop:
– What are we producing?
• Spools & their characteristics
• Joints & characteristics
– How are we producing them?
• Fabrication activities/flow
• Resources required

20. Simulation Model: Activity Flow

21. Simulation Model: Activities to Model
• Major pipe spool fabrication activities modeled:
 Cut
 Bevel
 Fit-up (& tack welding)
 Welding (auto and manual)
 QC inspection
 Post weld heat treatment (PWHT)
 Non-destructive testing (NDT)
 Painting
• For each activity, the type of resource (crew) required and its
relevant productivity were also identified

22. Simulation Model: Resources – Crew Composition
• Each pipe fabrication activity is associated with a
resource type
• Each resource type is typically a crew composed of a
group of workers required to perform a specific task
Typical crew compositions on a large industrial construction project
Crew Type
Worker
Type 1
Worker
Type 2
Worker
Type 3
Worker
Type 4
Worker
Type 5
Worker
Type 6
Worker
Type 7
Worker
Type 8
Worker
Type 9
Cut 1 2 1 2
Bevel 1
Fit-up 2 2 1 4
Weld Size 1 1 1
Weld Size 2 2 2
PWHT 1 2
Painting 1 3 4

23. Simulation Model: Resources - Histogram
• Workers available over the duration of the project
make up the required crews (resources) for the
fabrication activities
Typical worker availability over time on an industrial project
1 2 3 4 5 6 7 8
1 21 23 25 25 25 25 25 25
2 85 90 95 95 100 100 100 100
3 80 82 85 86 104 104 104 104
5 37 38 40 41 42 42 42 42
6 90 95 100 100 110 110 110 110
7 92 99 112 129 135 135 135 135
Worker
Type
Month

24. Simulation Model: Workflow to DES Model
Pipe Fabrication Activity Flow
Simulation Model

25. Simulation Model: DES Model

26. Simulation Model: Parameters Interface

27. Simulation Model: Data Inputs
• Spool and joint characteristics required for simulating
the fabrication activities were specified
Two-level hierarchy for spools and their relevant joints
Spool ID Stauts Material Paint Code Surface Area Priority
3 CS 6D 0.03 180
Weld # Weld Type Weld Inch-Dia PWHT Req'd NDT Req'd
2 SB 0.75 0 0
4 SB 0.75 0 0
5 SB 0.75 0 0
A140-A141-B92SL-15139D-S102 3 CS 6D 0.01 180
A140-A141-B92SL-15139D-S103 3 CS 6D 0.15 180
A140-A141-B92SL-15139D-S101

28. Simulation Model: Data Outputs
• The simulator produces a comprehensive set of data
comprised of the artificial history of the simulated pipe
fabrication operations
• The result set contains a record of the activities performed on
the corresponding entities (spools or welds) utilizing the
required resources:
– Simulated spool start / end dates and times for each status
– Simulated joints start / end dates and times for welding activities
– Crew man-hour requirements per simulated spool or joint activity
Scenario # Spool ID Weld No Activity Start Date and Time End Date and Time Resources
1304152 A140-A141-B92SL-15139D-S101 2 Welding 4/3/2013 11:01 4/3/2013 11:23 1
1304152 A140-A141-B92SL-15139D-S101 4 Welding 4/3/2013 11:01 4/3/2013 11:23 1
1304152 A140-A141-B92SL-15139D-S101 5 Welding 3/3/2013 15:01 3/3/2013 15:23 1
1304152 A140-A141-B92SL-15139D-S101 Painting 3/14/13 8:00 3/16/13 10:00 1

29. Benchmarking
• Multiple fab shop data collection exercises at large
CCC industrial construction projects in the Middle
East were performed to collect benchmark
productivity data for the simulator

30. Benchmarking
• Very practical information was collected by observing
the different fabrication shop operations:
– Actual uninterrupted work productivity timed from start
to finish with a total work scope and number of workers
involved
– Overall actual to-date production data for the
fabrication shops broken down by week including total
inch-dia and total manpower per week
– Daily worker hours breakdown in terms of breaks
related to the current heat index, lunch break, toolbox
talks, arrival and departure allowances, etc.

31. Case Study: Implementation on Large Gas Plant
Construction Project
Barzan Onshore Project
• Location: Ras Laffan Industrial City – Qatar
• Production Capacity: 2 bcfpd (Train 1 + Train 2)
• Contract: Barzan Central Contract, Package 1
(Process Area & Building Works)
• Client: QP and Exxon Mobil
• Main Contractor (EPC): Japan Gas Company (JGC)
• Scope: Construction of the process plant area, including piping fabrication
and erection, civil works, EPC buildings, steel structure erection,
equipment erection, E&I, painting, insulation and common scaffolding
Phase # of Joints Inch-Dia # of Spools # of ISO's
TRAIN 1 367,572 1,203,882 61,490 17,001
TRAIN 2 337,742 1,181,251 52,349 16,757

32. Case Study: Implementation on Large Gas Plant
Construction Project
Month
Total Inch-
Dia
Cut
Crew
Bevel
Crew
FitUp
Crew
Weld
Crew
Autoweld
Machines
Actual
Days
Sim
Days
October 50,798 6 20 30 90 8 28 27
November 61,217 10 20 30 102 8 30 30
December 67,091 15 25 40 118 8 31 29
January 68,220 14 24 38 113 8 31 30
February 70,848 15 25 40 137 8 28 25
March 78,159 15 25 40 156 8 31 24
Detecting Productivity Anomalies
• Fabrication activities on site were compared to
simulator runs to detect and emphasize productivity
anomalies
• We can notice a marked decline in February and
increase in March

33. Cut Bevel Fitup Weld
0% 48 51 53 54
10% 45 47 50 51
20% 39 41 44 45
30% 37 39 43 43
40% 33 36 38 39
50% 32 34 37 38
60% 31 33 36 38
70% 29 31 33 37
80% 27 30 32 37
90% 25 27 30 37
100% 24 26 29 37
Additional Cut / Bevel
/ Fitup Resources
Fabrication Activities End Day
Case Study: Implementation on Large Gas Plant
Construction Project
Detecting Bottlenecks and Optimizing Resource Mixes

34. Case Study: Implementation on Large Gas Plant
Construction Project
Activity Sim Start Date Sim End Date
Cut 3/2/13 8:00 3/3/13 17:01
Bevel 3/2/13 8:06 3/6/13 9:34
FitUp 3/2/13 8:13 3/9/13 17:06
Welding 3/2/13 8:00 3/30/13 17:18
NDT 3/2/13 19:00 5/16/13 5:00
PWHT 3/1/13 5:00 5/16/13 19:22
Blasting 3/2/13 6:00 5/18/13 14:30
Painting 3/2/13 14:30 5/21/13 16:30
Aea Sim Start Date Sim End Date
A110 3/1/13 5:12 3/17/13 10:00
A120 3/1/13 5:00 5/17/13 10:00
A130 3/1/13 5:00 3/22/13 16:00
A140 3/1/13 5:12 3/27/13 12:00
A150 3/1/13 5:00 3/30/13 10:00
A160 3/1/13 5:00 4/6/13 16:30
A170 3/1/13 5:12 5/17/13 10:00
A210 3/1/13 5:12 5/17/13 10:00
A220 3/1/13 5:00 5/17/13 10:00
A230 3/1/13 5:12 5/21/13 16:30
A240 3/27/13 11:27 5/17/13 10:00
A250 3/1/13 5:12 3/29/13 14:00
A260 3/6/13 6:00 5/21/13 16:30
A270 3/1/13 5:12 5/17/13 10:00
Forecasting Activity and Area Start and Completion Dates

35. Future Work
• Further development and enhancements to this
model include:
– A material constraint module (Material Forward
Planning)
– Full integration with CCC’s C3D construction
management software
– A pipe installation simulation model covering pipe
spool construction activities up to when spools are
installed on site and given final release

36. THANK YOU
Zuhair Haddad (ZUHAIR@CCC.ME)
Ramzi Labban (RLABBAN@CCC.COM.LB)