Resource Allocation: Smoothing and Levelling

Resource Allocation

Introduction

• A resource is a physical variable quantity such as material, labour, equipment, time or space which are required for carrying out a project.
• During planning stage, we generally assume that sufficient resources are allocated to perform the various activities and complete the project.
• But in reality resources are always limited, and this limitation of resources can significant affect the start, performance and completion of activities on scheduled time.
• For completion of projects in time and with in estimated cost, proper allocation and utilisation of resources is necessary.
• It is observed that resource availability fluctuate from very high at one time to very at other time during a year.
• Fluctuations in demand of an easily available resource like unskilled labour or some material will not cause much effect of the project.
• But if it is a rare available resource like skilled professional or some special equipment needed for project can not be made easily available, then they have to be hired or employed on permanent or semi permanent basis.
• Hence this will affect the cost of the project due to high idle time.
• Therefore, various activities of project should be scheduled in such a way that the demand for various resources is more less uniform during the project duration.

This can be achieved by following two approaches.

1 Resource smoothing

2. Resource levelling

Resource smoothing

• In resource smoothing the total project duration is not changed but the activities having floats are rescheduled such that a uniform demand for the resources is achieved.

 

IMPORTANT POINTS

• Project duration is not charged
• Resources are unlimited
• Critical path remains unchanged

 

Steps involved in resource smoothing.

• Last out the resources required for the completion of various activities and identify the one which are considered important.
• Prepare the resource profiles by carrying out the resource aggregation exercise and cumulative resource requirements for each unit are plotted in the form of histograms.
• Periods of peak and is demands are identified and an attempt is made to lower the peaks and fill up the gaps.
• As there is no constraint on the availability of resource, make the demand as uniform as possible.
• This can be achieved by altering the start and finishing times of the son critical activities these activities will have certain amount of float.

 

RESOURCE LEVELLING

• In resource levelling the activities are rescheduled such that maximum or peak demand of the resource does not exceed the availability of resources.

Important points

• Project duration might be changed.
• Resource are limited.
• Critical path may get changed.

 

Steps involved in Resource levelling

1. Lower the peak demand of the resources by shifting the resource input on non critical activities.
2. If required sub critical and critical activities are also changed or modified to bring the peak demand below the specified levels. Hence, completion of project might get delayed due to resource constraint.
3. Either increase the duration of critical activities in series to reduce the peak demand of rare or scare resource. This will increase the project duration.
4. Re-arrange the activities in descending order of the magnitude of positive float, as resource can be easily shifted from activities which possess large float. At first lower the high demand of resources by use of free floats. Then critical activities can be modified at last, if required.

OBJECTIVE QUESTIONS

1. Which of the following are the possible changes during the updating of the project network?

1. Change in the duration of an activity.

2. Addition or deletion of an activity.

3. Change in the logical relationship among the activities

Select the correct answer using the codes given below:

(a) 1, 2 and 3

(b) 1 and 2

(c) 2 and 3

(d) 1 and 3

 

2. What is the significant purpose of monitoring a project through its implementation phase?

(a) To fix responsibility for delays

(b) To rerail the project with control over cost over-run

(c) To rerail the project with minimum time over-run

(d) To rerail the project with optimal time and cost over-run

 

3. What is the process of incorporating changes and rescheduling or replanning called?

(a)Resource allocation

(b) Resource smoothing

(c) Resource levelling

(d) Updating

 

4. In resources levelling

(a) total duration of project is reduced

(b) total duration of project is increased

(c) uniform demand of resources is achieved

(d) cost of project in controlled

 

5. Consider the following statements:

Resource levelling means

1 economical utilization of resources

2 gradual increase in resources

3. adjustment of resources to have the least variations.

4. complete revamping of resources to suit the requirements

5. validating network depending on resource constraints

Which of these statements are correct?

(a) 1 and 2

(b) 2, 3 and 4

(c) 3 and 5

(d) 1, 2, 3, 4 and 5

 

6. Five activities are scheduled between time-3 days and time-14 days in a bar chart. Resource loading per day for these activities, along with their durations as read on the bar chart grid are:

Match List-I (Resource loading per day) with List-II (Day number) derived from above data and select the correct answer using the codes given below the lists:

List-I                      List-II

A. 16                   1. 12th

B. 15                    2. 14th

C. 14                   3. None

D. 12                   4. 11th

5. 8th

Codes:

A      B      C      D

(a)   3      4       5      2

(b)   4      3       1      5

(c)   4      2       5      1

(d)   3      4       1      5

 

7. In the network given below, the maximum number of shovels and dumpers required are

(a) 6 shovels and 14 dumpers on days 9 and 10

(b) 24 shovels and 10 dumpers on days 3 and 4

(c) 30 shovels and 90 dumpers on all days

(d) 10 shovels and 21 dumpers on days 3 and 4

Hints:

 

8. The activity duration (days) and resource requirements (unite) are shown in the figure below.

What is the maximum resource required in a day?

(a) 14 units

(b) 11 units

(c) 19 units

(d) 18 units

 

9. Consider the following statements:

1. The resources are considered to be unlimited.

2. The resources are considered to be limited.

3. The start times of some of the activities are so shifted within their available floats that the uniform demand is created for the resources.

Which of these statements is/are correct with respect resource levelling?

(a) 1 only

(b) 1, 2 and 3

(c) 2 and 3 only

(d) 1 and 3 only

 

10. Which of the following rules should be followed while doing the resource scheduling?

1. CPM network logic must be maintained.

2. Activities on the critical path must use normal crew size.

3. Activities on the non-critical path must use minimum crew size.

Select the correct answer unng the codes given below:

(a) 1, 2 and 3

(b) 1 and 2

(c) 1 and 3

(d) 2 and 3

 

11. The constraints in case of resource smoothing operation would be

(a) reunions

(b) project duration time

(c) both resources and project duration time

d) None of the above

 

12. In arriving at a resource-based schedule bar chart for a construction project, the following stages for planning of the work are involved

1. Finaliang a network of activities

2 Determining the optimal activity durations considering the relevant parameters

3. Computation of time and floata

4. Developing the resource hased bar chart and the corresponding hutograms and mass curves of resources

5 Identification of the critical constraining rescurce

6. Deciding the criteria for opumisation

The correct sequence of these stages in the planning of the work will be

(a) 1,6,2,3,5,4

(b) 6,2,1,3,4,5

(c) 1,2,3,6,5,4

(d) 2,1,3,5,6,4

The following items consist of two statements, one labelled as ‘Assertion A’ and the other labelled Reason R’ You are trexamirs these tein statements carefully and select your rewers to these itete using the codes given below.

Of these statements

(a) both A and R are true and R is the correct explanation of A

(b) both A and R are true but R is not a correct explanation of A

(c) A is true but R is false

(d) A is false but R is true

 

13. Assertion (A): In resource levelling, the project completion time is not extended even though there is constraint in the availability of resources.

Reason (R): There is generally a constraint against exceeding the project duration time.

 

14. Assertion (A): When attempting resource optimization, activity-time cost trade off information could be gainfully employed.

Reason (R): Generally, as activity time is extended beyond the minimum cost duration, splitting of the activity duration is always possible.

 

15. Assertion (A): In resource levelling approach of resource allocation, activity start times are scheduled such that the peak demand for a particular resource remains within available limit of the resources

Reason (R): In resource levelling approach of resource allocation, the total project time in not changed.