Efficient Scheduling of Repetitive Projects

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

Efficient Scheduling of Efficient Scheduling of Repetitive ProjectsRepetitive Projects

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

Agenda


HorizontalHorizontalDistributedDistributed

VerticalVertical

Linear & Repetitive Projects


Linear & 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

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

Acti

vity

Acti

vity

Task 5

Task 7Task 6Task 1

Task 4

Task 3

Task 2

Existing 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


Objectives

New Scheduling Model:New Scheduling Model:Better RepresentationBetter RepresentationWork Continuity Work Continuity Meet DeadlinesMeet Deadlines

Flexible PlanningFlexible Planning Cost Optimization Cost Optimization


Station 1

Station 2

Station n

Linear Scheduling Model


Site

Time

11 -

9 -

7 -

5 -

3 -

1 -

AB

C

D

C

rew

s: 3

4

3

3

End

Dat

e

New Representation

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


C = D x C = D x RR

Crew 2

Crew 1

Crew 3

Crew 2

Crew 1

Unit5

0 1 2 3 Time

1

2

3

4

Su = Su-1 + 1/Ri

Fu = Su + Di

One Activity - 3 CrewsOne Activity - 3 Crews

Work Continuity

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

1

4

5

3

6

2

9

8

7

Units3 Parallel Crews3 Stagg. Crews

Work Continuity

Color coded Crews


Stat

ion

Time

1

4

5

3

6

2

9

8

7

A DB C

Low Pr

Crew 3

Crew 2

Crew 1

Crew 2

Crew 1

Scheduling Flexibility

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

B: B: work work interruptiointerruption 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)


Optional Construction Methods

Resource DataResource Data

MaterialMaterial

SubsSubs

CrewCrewLaborLabor

EquipmentEquipment

Cost Cost OptimizationOptimization

Method Method 33Method Method 22Method Method 11

Activity Activity ii

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

ExpensiveExpensive


Cost Optimization

Complex Problem – Genetic Optimization

Direct Cost + Indirect Cost + Direct Cost + Indirect Cost + Penalty/IncentivePenalty/Incentive

Objective Objective Function:Function:

Duration <= DeadlineDuration <= DeadlineIndividual Resources <= Max. AllowedIndividual Resources <= Max. Allowed

Constraints: Constraints:

No. of Crews No. of Crews Work Methods (3 options)Work Methods (3 options)

Variables:Variables:


Different Implementations


Example3 Km highway, each station is 300 m

(i.e., 10 stations)

1. Highway Application

Right of Way


Data of activities, project constraints, and productivity data



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

3322

10101.21.211222222

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 toto55

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 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

2. 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 InstallationWindows Installation



Standard Vs Non-Standard floorsStandard Vs Non-Standard floors

Time

1

10

Floor20

Structural 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



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



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)



Infrastructure Management

Systems

Execution order?Outsourcing?

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

Execution Planning

List of Priority Assets & Repair Types

M&R Planning

3. Distributed Sites


End0 1 2 3 Time4 5 6

Crew 1

Crew 2

Site 5

Site 5

Site 1

Site 1

Site 2

Site 2

Site 3

Site 3

Site 4

Site 4

Crew 1

Crew 2

Crew 1

Crew 2

Repair

Acti

vity

Repair Activity for

Five SchoolsCrew 1

Distributed 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

In-House Resources

Outsourcing + Out-Tasking

Combination of All

MR&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:

Features

1. Resource Depository:


Real-Life Application

- Activitiies, - Activitiies,

- Logical - Logical RelationsRelations

- Three - Three Estimates.Estimates.

Slow & Cheap Slow & Cheap OptionOption

Fast & Fast & Expensive Expensive

OptionOption


Data inputs Data inputs for activity for activity delivery delivery and and constraintsconstraints



Real-Life ApplicationInitial 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


VisualizationAutomateAutomatedDispatch dDispatch MapsMaps


VisualizationAutomateAutomatedDispatch dDispatch MapsMaps


Benefits

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


EasyPlan DEMODEMO www.civil.uwaterloo.ca/tare

k

Efficient Scheduling of Repetitive Projects

Documents