5b- resource leveling and allocation

8/10/2019 5b- Resource Leveling and Allocation

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Tutorial # 5b

Allocate and Level

Resources

(Part B, Limited ResourceAllocation)

King Saud University

College of Engineering

GE 404 Engineering Management



Limited Resource Allocation

Main

Aspects

Also often called

constrained

-

resource

scheduling,

There are definite limitations on the amount of resources

available to carry out the project (or projects) underconsideration.

Project duration may increase beyond the initial duration

determined by the usual “time only” CPM calculations.

The scheduling objective is to minimize the duration of the project (or projects) being scheduled, subject to stated

constraints on available resources.



Limited Resource Allocation

START

Set ES of the START activity equals 1, calculate initial early start (ES) and late start (LS)

time for each activity in the project, and set time now equal to 1, i.e., T = 1.

Determine the initial eligible activity set (EAS), i.e., those activities with ES ≤ T and with all

predecessor activities completed.

From among the members of the current EAS, determine the ordered scheduling set (OSS) of

activities, i.e., activities with ES ≤ T, ordered according to LS with smallest values first andwithin this characteristic, according to least activity duration first.

Consider the activities in OSS in the order listed and schedule those activities for which

sufficient resources are available for the duration of the activity. As activities are scheduled

update the level of resources available, and update the members of EAS.

Have all activities been scheduled, i.e., is EAS an

empty set?

Set T new = T old + 1 and compute new ES times for the updated EAS.

STOPYes

No



Time 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

EAS

OSS

use

R

Form for solution



Example1:Solve the given resource scheduling problem assuming that 5 resources units

are allowed for any time during project duration. Also, identify which activity

(s) cause the project extension.

6 5 11

F

6 0 11

0 3 3

B

12 12 15

3 3 6

J

15 12 18

6 3 9

E

13 7 16

14 4 18

I

14 0 18

11 3 14

H

11 0 14

18 0 18

Finish

18 0 18

ES D EF

ActivityLS TF LF

Res

R2

R2 R2 R2R0

R2

R3 R3

R3 R5

0 0 0

Start

0 0 0

0 4 4

A

0 0 4

4 2 6

D

4 0 6

4 2 6

C

4 0 6

9 2 11

G

16 7 18



B D F H I

OSS A2

B3

J3 D0

C3

C3 F2

E2

G5 H2

G5

I2

G5

G5

A 2

B 3J 3

D 0

C 3

F 2

E 2

H 2

I 2

G 5

Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

5 5 5 5 3 3 3 3 4 4 4 2 2 2 2 2 2 2 2 2 5 5



Example2:

The program of a small contract is given

in table below. Each activity requires the

continues use of mechanical excavator

throughout its duration. What will be the

minimum contract duration if no morethan two excavators can be made

available for the work and if it is

assumed that having start activity it

must be completed without a break.

Activity Depends on Duration ES TF

A - 1 0 0

B A 2 1 3

C A 2 1 3

D A 3 1 0

E B 4 3 3

F C 5 3 3

G D 4 4 0

H E 1 7 3

I G 3 8 0

J H, I, G 1 11 0

EAS A B

C

D

E

C

E

G

E

F

F

I

I

H

H J

OSS D

B

C

C

E

G

E

E

F

F

I

I

H

H J

AD

B

C

G

E

F

I

H

J

Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

1 2 2 2 2 2 2 2 2 2 2 2 2 1

5b- resource leveling and allocation

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