Test: CPM & PERT - 1 - Civil Engineering (CE) MCQ

The critical path is the sequence of activities that represents the longest path through a project. It determines the shortest possible project duration.

The critical path can be easily determined with the help of total float calculations. The activities on the critical path are those activities that have total float equal to zero

i.e. TF = 0.

Independent Float

• It refers to the amount of time by which the start of an activity is can be delayed without affecting EST of any immediately following activity
• It is given by IF = FF – S_i  
• i.e. FF = IF + S_i
• If S_i = 0 → FF = IF = 0
• If S_i ≠ 0 FF > IF

1. Helps in planning efficient time schedule:

   • The critical path method (CPM) is used to identify the longest sequence of tasks in a project that must be completed on time for the project to be finished by its deadline. Knowing the critical path helps in planning an efficient time schedule by focusing on these critical tasks.

2. Indicates the shortest path in time:

   • This statement is incorrect. The critical path actually represents the longest path through the project, not the shortest. It determines the minimum project duration by identifying the sequence of dependent tasks that have the longest total duration.

3. Helps in crashing the project judiciously:

   • Crashing a project involves adding resources to critical path tasks to complete them more quickly, thus reducing the project duration. Identifying the critical path is crucial for effective crashing, as only tasks on the critical path will affect the overall project completion time.

4. Helps in encouraging discipline in execution:

   • By highlighting the tasks that cannot be delayed without affecting the project completion date, the critical path helps enforce discipline in execution. Project managers and team members can focus their attention on critical tasks to ensure they stay on track.

Therefore, the correct answer is: 1, 3 and 4

Solving the network will give earliest occurrence time (T_E) and latest finish time (T_L) as below:

LF - EF = total float.

Total float affects both preceding and succeeding activities.
Free float affects only succeeding activities.

Work is going on hence it is an activity.