Project Management using Program evaluation and Review technique (PERT) and Critical path method (CPM)

Based on the project scenario given below, answer the following questions

Scenario: Your organisation, ABC construction group has made a winning bid to construct a new manufacturing plant. The client expects the plant to be functional within a year. You are assigned as the Project Manager to ensure that the whole project stays on schedule. The two important conditions as per the client contract are:-

ABC construction group will incur a penalty if the work is not completed by the deadline of 47 weeks from now.

ABC construction group will be provided additional incentive if the work is completed within 40 weeks.

The table attached describes the activity list for ABC construction group for this project:-

For any given activity, its immediate predecessors (as given in the third column of Table) are those activities that must be completed by no later than the starting time of the given activity. (Similarly, the given activity is called an immediate successor of each of its immediate predecessors.) For example, the top entries in this column indicate that: -

Excavation does not need to wait for any other activities.

Excavation must be completed before starting to lay the foundation.

The foundation must be completely laid before starting to put up the rough wall, etc.

When a given activity has more than one immediate predecessor, all must be finished before the activity can begin. In order to schedule the activities, you have consulted with each of the crew supervisors to develop an estimate of how long each activity should take when it is done in the normal way. These estimates are given in the rightmost column of Table. Adding up these times gives a grand total of 79 weeks, which is far beyond the deadline for the project. Fortunately, some of the activities can be done in parallel, which substantially reduces the project completion time.

Activity Description Immediate Estimated duration predecessors A Excavate - 2 weeks B Lay the foundation A 4 weeks C Put up rough wall B 10 weeks D Put up the roof C 6 weeks E Install exterior plumbing C 4 weeks F Install interior plumbing E 5 weeks G Put up exterior siding D 7 weeks H Do exterior painting m 9 weeks I Do the electric work C 7 weeks I Put the wallboard E11. 8 weeks K Install the ooring .T 4 weeks L Interior painting I 5 weeks M Exterior xtures H 2 weeks N Interior xtures K,L 6 weeks