Cpm critical path method

Presentation of CPM

1. CPM – Critical Path Method

2. CPM – Critical Path Method Software Project Management 2 Maria Petridou It is determined by adding the times for the activities in each sequence. CPM determines the total calendar time required for the project. If activities outside the critical path speed up or slow down (within limits), the total project time does not change. The amount of time that a non-critical activity can be delayed without delaying the project is called slack-time .

3. CPM – Critical Path Method Software Project Management 3 Maria Petridou ET – Earliest node time for given activity duration and precedence relationships LT – Latest node time assuming no delays ES – Activity earliest start time LS – Activity latest start time EF – Activity earliest finishing time LF – Activity latest finishing time Slack Time – Maximum activity delay time

4. Dummy Activities Software Project Management 4 Maria Petridou Sometimes it is necessary to insert dummy activities (duration zero) in order to maintain the clarity of the diagram and the precedence relationships between activities. In activity-on-arrow PERT diagrams, each activity must be uniquely identifiable by its start and end nodes. However , sometimes multiple tasks have the same predecessors and successors.

5. Dummy Activities Software Project Management 5 Maria Petridou Case One A task should be uniquely identifiable from its start node and finish node This means that two or more tasks cannot share the same start and finish nodes 1 2 3 4 A D C Tasks B and C have the same start and finish nodes Task D has immediate predecessors of B and C B

6. Network Planning Techniques Program Evaluation & Review Technique (PERT): Developed to manage the Polaris missile project Many tasks pushed the boundaries of science & engineering (tasks’ duration = probabilistic) Critical Path Method (CPM): Developed to coordinate maintenance projects in the chemical industry A complex undertaking, but individual tasks are routine (tasks’ duration = deterministic)

7. PERT and CPM Graphically display the precedence relationships & sequence of activities Estimate the project’s duration Identify critical activities that cannot be delayed without delaying the project Estimate the amount of slack associated with non-critical activities

8. 8 Project Activities in Constructing a House

9. 9 PERT Network for Constructing a House