1. PERT/CPM By Bhupendra Ratha, Lecturer S. L. I. Sc., D.A.V.V., Indore Email Id: bhu261@gmail.com bhu261@gmail.com

2. PERT Project Evaluation and Review Technique (PERT) Project Evaluation and Review Technique (PERT) –U S Navy (1958) for the POLARIS missile program –Multiple task time estimates (probabilistic nature) –Activity-on-arrow network construction –Non-repetitive jobs (R & D work)

3. Need of PERT/CPM Prediction of deliverables Prediction of deliverables Planning resource requirements Planning resource requirements Controlling resource allocation Controlling resource allocation Internal program review Internal program review External program review External program review Performance evaluation Performance evaluation Uniform wide acceptance Uniform wide acceptance

4. Use of PERT In construction activities In construction activities Transportation activities Transportation activities In oil refineries In oil refineries Computer system- Computer system- For manufacturing electric generator machines For manufacturing electric generator machines Medical and surgical sector Medical and surgical sector Library activities Library activities

5. Importance of PERT system Reduction in cost Reduction in cost Saving of time Saving of time Determination of activities Determination of activities Elimination of risk in complex activities – Elimination of risk in complex activities – Flexibility Flexibility Evaluation of alternatives- Evaluation of alternatives- Useful in effective control- Useful in effective control- Useful in decision making Useful in decision making Useful is research work Useful is research work

6. History of CPM Critical Path Method (CPM) Critical Path Method (CPM) –E I Du Pont de Nemours & Co. (1957) for construction of new chemical plant and maintenance shut-down –Deterministic task times –Activity-on-node network construction –Repetitive nature of jobs

7. CPM calculation Path Path –A connected sequence of activities leading from the starting event to the ending event Critical Path Critical Path –The longest path (time); determines the project duration Critical Activities Critical Activities –All of the activities that make up the critical path

8. Procedure of PERT/CPM Develop a list of activities that make up project. Develop a list of activities that make up project. Estimate the completion time for each activity. Estimate the completion time for each activity. Draw a project network and t Draw a project network and t

9. Benefits of CPM/PERT Useful at many stages of project management Useful at many stages of project management Mathematically simple Mathematically simple Give critical path and slack time Give critical path and slack time Provide project documentation Provide project documentation Useful in monitoring costs Useful in monitoring costs

10. Limitations to CPM/PERT Clearly defined, independent and stable activities Clearly defined, independent and stable activities Specified precedence relationships Specified precedence relationships Over emphasis on critical paths Over emphasis on critical paths Deterministic CPM model Deterministic CPM model Activity time estimates are subjective and depend on judgment Activity time estimates are subjective and depend on judgment PERT assumes a beta distribution for these time estimates, but the actual distribution may be different PERT assumes a beta distribution for these time estimates, but the actual distribution may be different PERT consistently underestimates the expected project completion time due to alternate paths becoming critical PERT consistently underestimates the expected project completion time due to alternate paths becoming critical