The primary difference between CPM and PERT is that:

Correct option is C

Introduction:

The primary difference between Program Evaluation and Review Technique (PERT) and Critical Path Method (CPM) lies in their approach to time estimation and project scheduling:

1. PERT (Program Evaluation and Review Technique):

   • Used for projects where activity durations are uncertain.

   • Uses three-time estimates for each activity to incorporate uncertainty:

     • Optimistic time (O): Minimum possible time required.

     • Most likely time (M): Time taken under normal conditions.

     • Pessimistic time (P): Maximum possible time required.

   • These estimates help calculate the expected time (TE) using the formula:

     Expected Time (TE) = (Optimistic Time + 4 × Most Likely Time + Pessimistic Time) ÷ 6

   • PERT follows a probabilistic approach, making it suitable for R&D and new product development projects.

2. CPM (Critical Path Method):

   • Used for projects where activity durations are deterministic (known with certainty).

   • Uses only one-time estimate per activity.

   • Based on cost optimization, CPM helps determine the critical path to minimize project duration.

   • CPM is widely used in construction, production, and engineering projects.

     Information Booster:

• PERT is event-oriented, meaning it focuses on when events occur in a project timeline.

• CPM is activity-oriented, meaning it focuses on the time and cost required for each activity.

• PERT is best suited for unpredictable, non-repetitive projects, such as research and development.

• CPM is best for repetitive, predictable projects, such as construction or manufacturing.

• PERT does not focus on cost, whereas CPM integrates time and cost analysis.

• Both methods use network diagrams to represent project activities and dependencies.

  Additional Knowledge:
  

(a) PERT has one time estimate and CPM has three time estimates.
Incorrect:

• PERT does not use a single time estimate; instead, it uses three-time estimates (Optimistic, Most Likely, and Pessimistic).

• CPM does not use three-time estimates; it uses only one deterministic time estimate for each activity.

(b) PERT has two time estimates and CPM has three time estimates.
Incorrect:

• PERT does not use two-time estimates; it uses three (Optimistic, Most Likely, Pessimistic).

• CPM does not use three-time estimates; it relies on a single fixed time estimate for each task.

(d) PERT makes the assumption that activity times are known with certainty, and CPM employs three estimates to compute expected values.
Incorrect:

• PERT assumes uncertainty and uses three estimates, not fixed values.

• CPM does not use three-time estimates; it assumes certain and fixed time durations for activities.