© Tarek Hegazy – 1 Efficient Scheduling of Repetitive Projects Prof. Tarek Hegazy Computer-Aided Construction Project Management,

© Tarek Hegazy – www.civil.uwaterloo.ca/tarek 1

Efficient Scheduling of Efficient Scheduling of

Repetitive ProjectsRepetitive ProjectsEfficient Scheduling of Efficient Scheduling of

Repetitive ProjectsRepetitive Projects

Prof. Tarek Hegazy

Prof. Tarek HegazyComputer-Aided Construction

Project Management, & Infrastructure Asset Management


Linear & Repetitive Projects Linear & Repetitive Projects

Problems with Existing ToolsProblems with Existing Tools

Proposed Management ModelsProposed Management Models

ImplementationsImplementations Highway ApplicationHighway Application

High-Rise ApplicationHigh-Rise Application

Distributed Sites ApplicationDistributed Sites Application

ConclusionConclusion

Linear & Repetitive Projects Linear & Repetitive Projects

Problems with Existing ToolsProblems with Existing Tools

Proposed Management ModelsProposed Management Models

ImplementationsImplementations Highway ApplicationHighway Application

High-Rise ApplicationHigh-Rise Application

Distributed Sites ApplicationDistributed Sites Application

ConclusionConclusion

AgendaAgenda


HorizontalHorizontalDistributedDistributed

VerticalVertical

Linear & Repetitive ProjectsLinear & Repetitive Projects


Linear & Repetitive ProjectsLinear & Repetitive Projects

Various Types:Various Types:Horizontal, Vertical, & Distributed

Large Size & Many ResourcesLarge Size & Many Resources

Combination of In-House & OutsourcingCombination of In-House & Outsourcing

Complex to Schedule & ControlComplex to Schedule & Control

Sensitive to EnvironmentSensitive to Environment

Stringent Deadlines & BudgetsStringent Deadlines & Budgets

Various Types:Various Types:Horizontal, Vertical, & Distributed

Large Size & Many ResourcesLarge Size & Many Resources

Combination of In-House & OutsourcingCombination of In-House & Outsourcing

Complex to Schedule & ControlComplex to Schedule & Control

Sensitive to EnvironmentSensitive to Environment

Stringent Deadlines & BudgetsStringent Deadlines & Budgets

© Tarek Hegazy – www.civil.uwaterloo.ca/tarek 5TimeTimeTimeTime

Acti

vit

yA

cti

vit

yA

cti

vit

yA

cti

vit

y

Task 5Task 5

Task 7Task 7Task 6Task 6Task 1Task 1

Task 4Task 4

Task 3Task 3

Task 2Task 2

Existing ToolsExisting Tools Not suitable for Not suitable for

repetitive projectsrepetitive projects

No legible view of No legible view of

the large project the large project

datadata

Inadequate Inadequate

planning planning

No cost No cost

Optimization Optimization

Not suitable for Not suitable for

repetitive projectsrepetitive projects

No legible view of No legible view of

the large project the large project

datadata

Inadequate Inadequate

planning planning

No cost No cost

Optimization Optimization


Objectives Objectives

New Scheduling Model:New Scheduling Model:Better RepresentationBetter Representation

Work Continuity Work Continuity

Meet DeadlinesMeet Deadlines

Flexible PlanningFlexible Planning

Cost Optimization Cost Optimization

New Scheduling Model:New Scheduling Model:Better RepresentationBetter Representation

Work Continuity Work Continuity

Meet DeadlinesMeet Deadlines

Flexible PlanningFlexible Planning

Cost Optimization Cost Optimization


Station 1

Station 2

Station n

Linear Scheduling ModelLinear Scheduling Model


Sit

eS

ite

TimeTime

11 -

9 -

7 -

5 -

3 -

1 -

11 -

9 -

7 -

5 -

3 -

1 -

AB

C

D

AB

C

D

C

rew

s:

3

4

3

3

Cre

ws:

3

4

3

3

En

d

Dat

eE

nd

D

ate

New RepresentationNew Representation

How to Design the Schedule?How to Design the Schedule?1 3 5 7 9 11 13 15 17 19 21 23 25 271 3 5 7 9 11 13 15 17 19 21 23 25 27


C = D x C = D x RRC = D x C = D x RR

Crew 2Crew 2

Crew 1Crew 1

Crew 3Crew 3

Crew 2Crew 2

Crew 1Crew 1

UnitUnit

55

00 11 22 33 Time Time

11

22

33

44

Su = Su-1 + 1/Ri

Fu = Su + Di

Su = Su-1 + 1/Ri

Fu = Su + Di

One Activity - 3 CrewsOne Activity - 3 CrewsOne Activity - 3 CrewsOne Activity - 3 Crews

Work ContinuityWork Continuity

© Tarek Hegazy – www.civil.uwaterloo.ca/tarek 10Time

1

4

5

3

6

2

9

8

7

Units3 Parallel Crews3 Parallel Crews3 Stagg. Crews3 Stagg. Crews

Work ContinuityWork Continuity

Color coded Crews


Sta

tio

n

Time

1

4

5

3

6

2

9

8

7

A A DDB B CC

Low Pr

Crew 3

Crew 2

Crew 1

Crew 2

Crew 1

Scheduling FlexibilityScheduling Flexibility

A: A: single single

crew from crew from

units 3 to units 3 to

88

A: A: single single

crew from crew from

units 3 to units 3 to

88

C: C: crew crew

continuity continuity

under under

variable variable

durationsdurations

C: C: crew crew

continuity continuity

under under

variable variable

durationsdurations

B: B: work work

interruptiointerruptio

n at unit 6n at unit 6

B: B: work work

interruptiointerruptio

n at unit 6n at unit 6

D: D: red and red and

blue crews blue crews

move from move from

both sides both sides

at same at same

time time

(channel (channel

tunnel)tunnel)

D: D: red and red and

blue crews blue crews

move from move from

both sides both sides

at same at same

time time

(channel (channel

tunnel)tunnel)


Optional Construction MethodsOptional Construction Methods

Resource DataResource DataResource DataResource Data

MaterialMaterialMaterialMaterial

SubsSubsSubsSubs

CrewCrewCrewCrewLaborLaborLaborLabor

EquipmentEquipmentEquipmentEquipment

Cost Cost OptimizationOptimization

Cost Cost OptimizationOptimization

Method Method 33Method Method 33Method Method 22Method Method 22Method Method 11Method Method 11

Activity Activity ii

Activity Activity ii

From From Slow & Slow & CheapCheap to to Fast & Fast &

ExpensiveExpensive

From From Slow & Slow & CheapCheap to to Fast & Fast &

ExpensiveExpensive


Cost OptimizationCost Optimization

Complex Problem – Genetic OptimizationComplex Problem – Genetic Optimization

Direct Cost + Indirect Cost + Direct Cost + Indirect Cost +

Penalty/IncentivePenalty/Incentive

Objective Objective Function:Function:

Objective Objective Function:Function:

Duration <= DeadlineDuration <= Deadline

Individual Resources <= Max. AllowedIndividual Resources <= Max. Allowed

Constraints: Constraints: Constraints: Constraints:

No. of Crews No. of Crews

Work Methods (3 options)Work Methods (3 options)

Variables:Variables: Variables:Variables:


Different ImplementationsDifferent Implementations


Example3 Km highway, each station is 300 m

(i.e., 10 stations)

1. Highway Application1. Highway Application

Right of Way


Data of activities, project constraints, and productivity data



Estimate 1Estimate 1 Estimate 2Estimate 2 Estimate 3Estimate 3

StationStation Max.Max.CrewsCrews

($)($) (d)(d) ($)($) (d)(d) ($)($) (d)(d)

1. Excavation, E.1. Excavation, E.2. Sub-base, East2. Sub-base, East3. Base, East3. Base, East4. Binder, East4. Binder, East5. Asphalt, East5. Asphalt, East6. Curbs, East6. Curbs, East7. Lighting, East7. Lighting, East8. Sidewalks, E.8. Sidewalks, E.9. Paint , East9. Paint , East

1 1 toto

1010

222233111111222211

21 K21 K7.8 K7.8 K72 K72 K30 K30 K

14.4 K14.4 K31.2 K31.2 K19.2 K19.2 K11 K11 K

332210101.21.211222222

30 K30 K--------

80 K80 K----------------

38 K38 K25 K25 K--------

22--------88

----------------1111

--------

----------------

100 K100 K----------------------------------------

----------------55

----------------------------------------

198198 0.20.2 -------- -------- -------- --------

Data of activities’ optional estimates

Means Cost Data



StationStation

1. Excavation, East1. Excavation, East2. Sub-base, East2. Sub-base, East3. Base, East3. Base, East4. Binder, East4. Binder, East5. Asphalt, East5. Asphalt, East6. Curbs, East6. Curbs, East7. Lighting, East7. Lighting, East8. Sidewalks, East8. Sidewalks, East

1 1 toto

55

9. Paint9. Paint 11 to to 1010

10 to 1710 to 17. Same as 1-. Same as 1-8 but at West Side8 but at West Side 1010 to to 66

Construction MethodTWO set of Crews moving from Both Sides



User input of the three estimates



West Sections

East Sections

Deadline not met

Click on any activity to get detailed schedule

data

Color-coded crews.

Options

1. Highway Application1. Highway ApplicationInitial schedule


Deadline met

After Optimization





Unique Considerations:

Structural–Core RepresentationStructural–Core Representation

Horizontal and Vertical Constraints Horizontal and Vertical Constraints

Weather and Learning Curve EffectsWeather and Learning Curve Effects

Introducing Proper Work InterruptionsIntroducing Proper Work Interruptions

Meet Project DeadlineMeet Project Deadline

Alternative Construction MethodsAlternative Construction Methods

Presenting a Clear & Realistic SchedulePresenting a Clear & Realistic Schedule

Structural–Core RepresentationStructural–Core Representation

Horizontal and Vertical Constraints Horizontal and Vertical Constraints

Weather and Learning Curve EffectsWeather and Learning Curve Effects

Introducing Proper Work InterruptionsIntroducing Proper Work Interruptions

Meet Project DeadlineMeet Project Deadline

Alternative Construction MethodsAlternative Construction Methods

Presenting a Clear & Realistic SchedulePresenting a Clear & Realistic Schedule

2. High-Rise Application2. High-Rise Application


Vertical Constraints: Dependences among activities on Vertical Constraints: Dependences among activities on Different FloorsDifferent Floors

1

2

3

4

5

t2

B BFloor

Time

t3t1 Shift Time

A

Shoring Removal

Pre-Cast panels Installation

Windows Installation



Standard Vs Non-Standard floorsStandard Vs Non-Standard floors

Time

1

10

Floor

20Structural Core activities after reduction

Structural Core activities before reduction



Ground Floor

Residential Floors- 8th to 13th (50% of Standard Floors)

Sketch of Hypothetical Building

Basement 1

2

11

5

4

3

10

6

7

9

8

13

12

CPM Network for The Case-

Study



Activities Cost and Durations



Project Constraints

Deadline = 11 months (220 working days)Deadline = 11 months (220 working days)

Total Budget : $17 millionsTotal Budget : $17 millions

Indirect Cost: $5,000 per dayIndirect Cost: $5,000 per day

Liquidated Damage: $100,000 per dayLiquidated Damage: $100,000 per day

Incentives: 10,000 per dayIncentives: 10,000 per day

3 Construction methods / Activity3 Construction methods / Activity

Monthly productivity factorsMonthly productivity factors

Floor changes at the 8th levelFloor changes at the 8th level

Deadline = 11 months (220 working days)Deadline = 11 months (220 working days)

Total Budget : $17 millionsTotal Budget : $17 millions

Indirect Cost: $5,000 per dayIndirect Cost: $5,000 per day

Liquidated Damage: $100,000 per dayLiquidated Damage: $100,000 per day

Incentives: 10,000 per dayIncentives: 10,000 per day

3 Construction methods / Activity3 Construction methods / Activity

Monthly productivity factorsMonthly productivity factors

Floor changes at the 8th levelFloor changes at the 8th level



Data InputData Input



Specifying ConstraintsSpecifying Constraints



Initial ScheduleInitial Schedule

Optimization Needed!Optimization Needed!



Schedule OptimizationSchedule Optimization

Resources Vs DeadlineResources Vs Deadline

Number of CrewsNumber of Crews

Construction MethodsConstruction Methods

InterruptionInterruption

No. CyclesNo. Cycles

Resources Vs DeadlineResources Vs Deadline

Number of CrewsNumber of Crews

Construction MethodsConstruction Methods

InterruptionInterruption

No. CyclesNo. Cycles



ResultsResults

Structural Activities

Pre-cast Panels

StudWindows

Vertical Constraints Are MetVertical Constraints Are Met



Visualization ReportsVisualization Reports

Very Useful for Site Personnel During Project Control Very Useful for Site Personnel During Project Control



3. Projects with Multiple Distributed Sites (e.g., Multiple

Houses)

3. Projects with Multiple Distributed Sites (e.g., Multiple

Houses)



Infrastructure Management

Systems

Infrastructure Management

Systems

Execution order?Outsourcing?

In-house resources?Meet Strict deadline?Normal / Overtime?

Execution order?Outsourcing?

In-house resources?Meet Strict deadline?Normal / Overtime?

Execution Planning

Execution Planning

List of Priority Assets & Repair Types

List of Priority Assets & Repair Types

M&R PlanningM&R Planning

3. Distributed Sites3. Distributed Sites


EndEnd

00 11 22 33 Time Time44 55 66

Crew 1Crew 1

Crew 2Crew 2

Site 5

Site 5Site 5

Site 1

Site 1Site 1

Site 2

Site 2Site 2

Site 3

Site 3Site 3

Site 4

Site 4Site 4

Crew 1Crew 1

Crew 2Crew 2

Crew 1Crew 1

Crew 2Crew 2

Repair

Acti

vity

Repair Activity for

Five Schools

Repair Activity for

Five SchoolsCrew 1Crew 1

Distributed SchedulingDistributed Scheduling

Determines: Crews, Work Determines: Crews, Work Methods, & Site Order that Methods, & Site Order that Meet Deadline with Minimum Meet Deadline with Minimum Cost.Cost.

Crew Moving – Delivery Crew Moving – Delivery MethodsMethods


Delivery Approaches for MR&R Programs

Delivery Approaches for MR&R Programs

In-House Resources

In-House Resources

Outsourcing + Out-Tasking

Outsourcing + Out-Tasking

Combination of All

Combination of All

MR&R Delivery OptionsMR&R Delivery Options


Activities

i

Timecost

Timecost

Timecost

2. Built-In Auto-Estimates:

Work assignment options:Normal work, Overtime, or Weekends

- Work continuity - Enhanced presentation

Optimum values of: - Order of execution - Work assignment option - Activity Crews - Crew non-work periods

Planning

Cost Optimization

- Project status - Progress Updates

Optimum corrective

actions

Actual

Progress

Re-Optimization

oOrder of execution oContractors vs in-houseo Automated Estimateso Crew Work Continuityo Deadline Durationo Resource limitso Specific Site Conditionso Crew Movement Time/Costo GIS-based site distanceso PalmTM – based progress

3. Planning & Control:

FeaturesFeatures

1. Resource Depository:


Real-Life ApplicationReal-Life Application

- Activitiies, - Activitiies,

- Logical - Logical

RelationsRelations

- Three - Three

Estimates.Estimates.

- Activitiies, - Activitiies,

- Logical - Logical

RelationsRelations

- Three - Three

Estimates.Estimates.

Slow & Cheap Slow & Cheap OptionOption

Slow & Cheap Slow & Cheap OptionOption

Fast & Fast & Expensive Expensive

OptionOption

Fast & Fast & Expensive Expensive

OptionOption


Data inputs Data inputs

for activity for activity

delivery delivery

and and

constraintsconstraints

Data inputs Data inputs

for activity for activity

delivery delivery

and and

constraintsconstraints



Real-Life ApplicationReal-Life ApplicationInitial Initial ScheduleSchedule

Two Two Outsourced Outsourced sites sites

Deadline Deadline

not metnot met

Initial Initial ScheduleSchedule

Two Two Outsourced Outsourced sites sites

Deadline Deadline

not metnot met



Deadline met at Deadline met at Min. cost.Min. cost.

Schedule => Schedule => GISGIS

Deadline met at Deadline met at Min. cost.Min. cost.

Schedule => Schedule => GISGIS


VisualizationVisualizationAutomateAutomatedDispatch dDispatch MapsMaps

AutomateAutomatedDispatch dDispatch MapsMaps


VisualizationVisualizationAutomateAutomatedDispatch dDispatch MapsMaps

AutomateAutomatedDispatch dDispatch MapsMaps


BenefitsBenefits

Cost-Effective deliveryCost-Effective delivery

In-house vs outsourcing vs out-taskingIn-house vs outsourcing vs out-tasking

Ties to Asset Management SystemsTies to Asset Management Systems

Realistic execution to meet constraints Realistic execution to meet constraints

Do more for less & reduce backlogDo more for less & reduce backlog

Speedy corrective actionsSpeedy corrective actions

Cost-Effective deliveryCost-Effective delivery

In-house vs outsourcing vs out-taskingIn-house vs outsourcing vs out-tasking

Ties to Asset Management SystemsTies to Asset Management Systems

Realistic execution to meet constraints Realistic execution to meet constraints

Do more for less & reduce backlogDo more for less & reduce backlog

Speedy corrective actionsSpeedy corrective actions


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© Tarek Hegazy – 1 Efficient Scheduling of Repetitive Projects Prof. Tarek Hegazy Computer-Aided Construction Project Management,