(VII) OPTIMIZATION 1

OPTIMIZATION IN CHASTROBE

WITH GENETIC ALGORITHM

Optimizing Project Duration and Idle Time in a Repetitive Project with Work Breaks and

Resource-Sharing Activities

Presented by

Chachrist Srisuwanrat

2008

(VII) OPTIMIZATION 2

OPTIMIZATION IN CHASTROBE

Three Levels of Simulation Code and

Model Manipulation

• Parameter Manipulation

• Simulation Code Manipulation

• Simulation Model Manipulation

Two Search Methods

• The Exhaustive Search

• The Genetic Algorithm

(VII) OPTIMIZATION 3

Flowchart of ChaStrobe’s Optimization

(VII) OPTIMIZATION 4

GA OPTIMIZATION IN

CHASTROBE

(VII) OPTIMIZATION 5

GA OPTIMIZATION IN

CHASTROBE (Cont.)

(VII) OPTIMIZATION 6

Decision Variable Cells and Dynamic

Code Input

(b) Dynamic Code Input, Simulation

Code, and Cells referencing the

Decision Variable Cells

(a) Search Input, Decision Variable

Cells in Row 2, and Domain Values

for each Decision Variables

(VII) OPTIMIZATION 7

Dynamic Code Positions

(VII) OPTIMIZATION 8

User-Specified Objective Function in

Additional Code

Objective Function stored in ObjFunc variable,

and additional user-specified output

(VII) OPTIMIZATION 9

Search Parameters for Optimization

(VII) OPTIMIZATION 10

Intermediate Results from GA

Optimization

(VII) OPTIMIZATION 11

Example of ChaStrobe’s Optimization

for a Repetitive Project with Resource-

Sharing Activities and Work Breaks

ACT Variability

Unit

1 2 3 4 5

Duration

A Normal[1,0.1] 40 45 40 40 45

M Normal[1,0.1] 15 15 10 10 10

B Normal[1,0.1] 50 40 50 50 40

X Normal[1,0.1] 20 30 25 20 20

U Normal[1,0.1] 15 20 15 25 20

V Normal[1,0.1] 40 40 45 45 40

C Normal[1,0.1] 15 15 15 15 15

N Normal[1,0.1] 20 25 30 20 25

Y Normal[1,0.1] 20 20 20 20 20

D Normal[1,0.1] 45 35 40 40 30

A Normal[1,0.1] 40 45 40 40 45

(VII) OPTIMIZATION 12

Results

(VII) OPTIMIZATION 13

Results: An unusual up-and-down

pattern in project duration and idle Time

(VII) OPTIMIZATION 14

Optimization Input

(VII) OPTIMIZATION 15

Search Input and Dynamic Input Code

for Optimization

(VII) OPTIMIZATION 16

Objective Function

(VII) OPTIMIZATION 17

Flowchart of ChaStrobe’s Optimization

(VII) OPTIMIZATION 18

GA Results

Without optimization, the objective function value is -79 days

(1200 - project duration – project idle time = 1200-746 – 533)

(VII) OPTIMIZATION 19

Results from using GA solution

Objective Function Value is derived from:

1200 – Project Duration – Project Idle Time

Method Project

Duration

Project

Idle time

Objective

Function

Value

CPM 416 944 -160

SQS-AL 746 533 -79

SQS-AL* 591 21 588