Resources Managementosp.mans.edu.eg/elbeltagi/R 4 Resources.pdf · 3 30/10/2014 Emad Elbeltagi 5 Activity Duration (Weeks) Resources (units/week) A B C D E 2 3 2 5 2 Shown in the

1

Resources

Management

Resources

Management

30/10/2014 Emad Elbeltagi 2

Resources ManagementResources Management

What a resource?

� Any thing that is used by an activity to get the work done,

such as: Material, Equipment, Labor, Money, …..

� Resources can be classified as:

� Consumable (Money, Material,……)

� Non Consumable (Labor, Equipment,…)

What a resource?

� Any thing that is used by an activity to get the work done,

such as: Material, Equipment, Labor, Money, …..

� Resources can be classified as:

� Consumable (Money, Material,……)

� Non Consumable (Labor, Equipment,…)

2



Duration-Driven Schedule

� All CPM scheduling techniques are duration driven schedules

� Basic units: activities, durations, relationships

� Assumes resources are available whenever needed

� Also, resources can be classified as:

� Key or constrained resources (Skilled labor, Equipment,……)

� Secondary or non-constrained resources (Labor, …)

� General resources, used by all activities

Duration-Driven Schedule

� All CPM scheduling techniques are duration driven schedules

� Basic units: activities, durations, relationships

� Assumes resources are available whenever needed

� Also, resources can be classified as:

� Key or constrained resources (Skilled labor, Equipment,……)

� Secondary or non-constrained resources (Labor, …)

� General resources, used by all activities



Resource aggregation or Resource loading

� The summation, on a period-by-period basis, of the

resources required to complete all activities based on the

schedule carried out in the previous stage

� The results are usually shown graphically as a histogram

� A separate graph will be required for each resource


� The summation, on a period-by-period basis, of the

resources required to complete all activities based on the

schedule carried out in the previous stage

� The results are usually shown graphically as a histogram

� A separate graph will be required for each resource

3


Activity Duration (Weeks) Resources (units/week)

A

B

C

D

E

2

3

2

5

2

Shown in the histogram



� Consider the following activities


� Consider the following activities

� Resource limit = 10 units /week� Resource limit = 10 units /week



Resource aggregation or Resource loadingResource aggregation or Resource loading

Resource limitResource limit

4



Resource aggregation or Resource loadingResource aggregation or Resource loading


Resources ManagementResources ManagementProblems Associated with Resource

� Resource Fluctuation (Resource leveling)

� Resource Over allocation (Resource Scheduling)

Problems Associated with Resource

� Resource Fluctuation (Resource leveling)

� Resource Over allocation (Resource Scheduling)

Resource

Time

Resource profile with

high resource fluctuation

(High hiring and firing)

Resource

limit

Resource

Time

Less hiring and firing

(More stable work conditions)

5



Methods for Resolving Resource conflicts (Problems)

� Optimization Models (Utilize optimization techniques):

� Linear programming models

� Advantages: Provide optimum solution

� Limitations: Cannot be applied to large problems

� Heuristic Models (Utilize rule of thumb based on experience):

� Heuristic or rules of thumb

� Advantages: Can be applied to large problems

� Limitations: Do not provide optimum solution

Methods for Resolving Resource conflicts (Problems)

� Optimization Models (Utilize optimization techniques):

� Linear programming models

� Advantages: Provide optimum solution

� Limitations: Cannot be applied to large problems

� Heuristic Models (Utilize rule of thumb based on experience):

� Heuristic or rules of thumb

� Advantages: Can be applied to large problems

� Limitations: Do not provide optimum solution



Resource Leveling (Smoothing)Resource Leveling (Smoothing)Unconstrained resource scheduling (Constrained time)Unconstrained resource scheduling (Constrained time)

Resource Leveling

� Resource unconstrained (No limits on resources)

� Time (Project completion) constrained; project duration not

be delayed

� Reduce the difference between the peaks and the valleys

� Average resource usage

� The objective is to smooth the use of the resources to

avoid the resource fluctuation

Resource Leveling

� Resource unconstrained (No limits on resources)

� Time (Project completion) constrained; project duration not

be delayed

� Reduce the difference between the peaks and the valleys

� Average resource usage

� The objective is to smooth the use of the resources to

avoid the resource fluctuation

6



Resource Leveling (Smoothing)Resource Leveling (Smoothing)




Minimum Moment Algorithm = ∑ Yi * Yi /2Minimum Moment Algorithm = ∑ Yi * Yi /2

7




Heuristic Method Procedure

� Prepare a complete activity schedule

� Draw a bar chart based on ES timings

� Draw the FF as dashed line beside the upper side of the bar

and the TF beside the lower side

� Put the resource usage in each bar of the related activity

� Critical activities to be drawn first (do not move them)

� Aggregate the resources in each time period

Heuristic Method Procedure


� Draw a bar chart based on ES timings

� Draw the FF as dashed line beside the upper side of the bar

and the TF beside the lower side

� Put the resource usage in each bar of the related activity

� Critical activities to be drawn first (do not move them)





Procedure

� Calculate the total usage of resources = ∑ unit period usage

� Calculate the average resource usage = ∑ usage / utilization

period

� Shift non-critical activities within their FF first, then their TF to

decrease the peaks and raise the valleys

� Revise the activities float


Procedure

� Calculate the total usage of resources = ∑ unit period usage

� Calculate the average resource usage = ∑ usage / utilization

period

� Shift non-critical activities within their FF first, then their TF to

decrease the peaks and raise the valleys

� Revise the activities float


8



Resource Leveling (Example)Resource Leveling (Example)

ExampleExample

Activity Duration (Weeks) PredecessorsResource

(units/week)

A

B

C

D

E

F

G

H

I

J

K

L

M

N

0

2

5

3

2

6

6

6

4

2

7

3

2

2

-

1

1

1

2

2

3

4

4

5, 6

6, 7

2, 8

2, 8, 9

10, 11, 12, 13

0

0

2

2

1

2

3

1

0

4

2

2

4

0




A (0)

0 0

0 0

F (6)

5 11

2 8

B (2)

3 5

0 2

D (3)

6 9

0 3

I (4)

12 16

3 7

G (6)

5 11

5 11

H (6)

9 15

3 9

M (2)

16 18

9 11

J (2)

16 18

8 10

L (3)

15 18

9 12

K (7)

11 18

11 18

N (2)

18 20

18 20

C (5)

0 5

0 5

E (2)

14 16

2 4

9




Activity ES EF FF TF

A

B

C

D

E

F

G

H

I

J

K

L

M

N

0

0

0

0

2

2

5

3

3

8

11

9

9

18

0

2

5

3

4

8

11

9

7

10

18

12

11

20

0

0

0

0

4

0

0

0

2

8

0

6

7

0

0

3

0

6

12

3

0

6

9

8

0

6

7

0




0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

C, 2G, 3

K, 2N, 0

B, 0

D, 2

E, 1

F, 2

H, 1

I, 0

J, 4

L, 2

M, 4

4 ∑= 904 7 6 5 6 6 6 8 13 9 4 2 2 2 2 2 2

10




0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20



Resource Leveling (Example)Resource Leveling (Example)0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

C, 2G, 3

K, 2N, 0

B, 0

D, 2

E, 1

F, 2

H, 1

I, 0

J, 4

L, 2

M, 4

∑= 90

M (7 days) -4 -4 +4 +44 4 7 6 5 6 6 6 8 9 5 4 2 2 2 2 6 6

J (6 days) -4 -4 +4 +44 4 7 6 5 6 6 6 4 5 5 4 2 2 6 6 6 6

L (2 days) -2 -2 +2 +2

4 4 7 6 5 6 6 6 8 1 3 9 4 2 2 2 2 2 2

4 4 7 6 5 6 6 6 4 3 3 4 4 4 6 6 6 6

11



Resource Leveling (Example)Resource Leveling (Example)0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

C, 2G, 3

K, 2N, 0

B, 0

D, 2

E, 1

F, 2

H, 1

I, 0

J, 4

L, 2

M, 4

∑= 90

E (10 days) -1 -1 +1 +14 4 6 5 5 6 6 6 4 3 3 4 5 5 6 6 6 6

H (2 days) -1 -1 +1 +14 4 6 4 4 6 6 6 4 4 4 4 5 5 6 6 6 6

F (1 days) -2 +2

4 4 7 6 5 6 6 6 4 3 3 4 4 4 6 6 6 6

4 4 4 4 4 6 6 6 6 4 4 4 5 5 6 6 6 6




0

1

2

3

4

5

6

7

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

12



Resource SchedulingResource SchedulingConstrained resource scheduling (Unconstrained time)Constrained resource scheduling (Unconstrained time)

Resource Scheduling

� Constrained Resources

� Unconstrained project completion; project time may be delayed

� Reduce the resource usage to be less than the resource availability

� The objective is to meet the resources limits

Resource Scheduling

� Constrained Resources

� Unconstrained project completion; project time may be delayed

� Reduce the resource usage to be less than the resource availability

� The objective is to meet the resources limits



Resource SchedulingResource SchedulingR 2 A

2 B

1 C

1 D

2 E

R2 A

2 B

1 C

1 D

2 E

Resource limit = 2Resource limit = 2

2 2 2 2 1 1 2 2 2 2

2 2 4 4 1 1 2 2

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Resource SchedulingResource Scheduling

Is there is a way to prioritize activities

That compete for the limited resources

so that the net project delay is

minimized?

Is there is a way to prioritize activities

That compete for the limited resources

so that the net project delay is

minimized?




Resource Scheduling Rules of Thumb

� Many rules have been experimented with

� Least TF were found to be most effective

� Least LS has the same effect as the least TF and doesn’t

require network recalculations

� In case of a tie use least TF

Resource Scheduling Rules of Thumb

� Many rules have been experimented with

� Least TF were found to be most effective

� Least LS has the same effect as the least TF and doesn’t

require network recalculations

� In case of a tie use least TF

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Procedure


� Aggregate the daily resource demand

� If demand greater than available then determine activities

compete for resources

� Prioritize these activities based on their LS

� Allocate resources to some activities and delay the others

� Put your solution in table format

Procedure


� Aggregate the daily resource demand

� If demand greater than available then determine activities

compete for resources

� Prioritize these activities based on their LS

� Allocate resources to some activities and delay the others

� Put your solution in table format



Resource Scheduling (Example)Resource Scheduling (Example)

Activity Duration (Weeks) PredecessorsResource (units/week)

R1≤8 R2 ≤1

A

B

C

D

E

F

G

H

I

J

K

6

4

2

8

4

10

16

8

6

6

10

-

-

-

A

D

B

B

F

E, H

C

G, J

3

6

4

0

4

0

4

2

4

5

2

0

1

0

1

1

1

0

0

1

1

0

15



Resource Scheduling (Example)Resource Scheduling (Example)

Start (0)

0 0

0 0

F (10)

8 18

6 16

B (6)

0 6

0 6

I (6)

26 32

24 30

G (16)

6 22

6 22

J (6)

16 22

2 8

A (4)

10 14

0 4

H (8)

18 26

16 24

E (4)

22 26

12 16

K (10)

22 32

22 32

End (0)

32 32

32 32

C (2)

14 16

0 2

D (8)

14 22

4 12

3, 0

4, 0 5, 1

4, 06, 1

0, 1

0, 1 4, 1

2, 0 4, 1

2, 0

Current Time

Eligible Activities

ResourcesDuration

Earliest LS

DecisionFinish TimeR1≤8 R2 ≤1

0 B

A

C

6 1 6 0

3 0 4 10

4 0 2 14

Start

Delay

Delay

6

-

-

6 G

F

A

C

4 0 16 6

0 1 10 8

3 0 4 10

4 0 2 14

Start

Start

Start

Delay

22

16

10

-

10 G

F

C

D

4 0 16 -

0 1 10 -

4 0 2 14

0 1 8 14

Continue

Continue

22

16Start

Delay12

-

12 G

F

D

J

4 0 16 -

0 1 10 -

0 1 8 14

5 0 6 16

Continue

Continue

22

16Delay

Delay

-

-

16 G

D

J

H

4 0 16 -

0 1 8 14

5 1 6 16

2 0 8 18

Continue 22Start

Delay

Start

24

-

24

16

Current Time

Eligible Activities

ResourcesDuration

Earliest LS

DecisionFinish TimeR1≤8 R2 ≤1

22 D

H

J

0 1 8 -

2 0 8 -

5 1 6 16

24

24

24 J

E

5 1 6 14

4 1 4 22

30 Start

Start

34

40

Continue

40Start

Continue

Continue

Delay -

Start

Delay

30

-

E

K

4 1 4 22

2 0 10 22

34 K

I

2 0 10 -

2 0 6 26

40

Documents

Resources Managementosp.mans.edu.eg/elbeltagi/R 4 Resources.pdf · 3 30/10/2014 Emad Elbeltagi 5 Activity Duration (Weeks) Resources (units/week) A B C D E 2 3 2 5 2 Shown in the