Compressing the Project Duration ( or)

Compressing Project Duration

1. Get the Critical Path of the Activity Precedence Diagram using normal times and compute the free float times for non critical activities. 2. Compute the cost-duration slope for all the project activities using formula Cost-duration slope = Cc - Cn Dn - Dc 3. Focus on the critical activities since by reducing their duration, you automatically reduce the entire project duration. 4. Investigate and identify the critical activity with the SMALLEST cost-duration slope ( since compressing it will result in smallest incremented cost). 5. Once critical activity with the smallest cost-duration has been identified, determine Crash Limit = [ Normal duration - Crash duration] for identified critical activity with smallest slope. 6. Determine the free float limit by reducing the duration of identified critical activity by one (1) unit. Get the critical path and recomputed the FF values for non critical activities. 7. Investigate which among the non critical activities have their FF value reduce by ONE unit as result of reduction of one unit the duration of identified critical activity. FF limit = smallest FF value BEFORE the reduction of one unit duration for the identified critical activity. Note: FF limit is investigated for there is a possibility that a non-critical activity with FF= O may turn out critical after all. 8. Compression limit = min [crash limit, FF limit]. Note: if the crash limit is one, there is no need to get the FF limit as a value 1 is the absolute minimum and is assigned as the compression limit automatically. 9. Reduce the project duration by the compression limit, determine the critical path and FF values of non critical activities.

10. Repeat steps 4 to 8 until all the critical activities in the critical path have reached their crash limits. If the crash limits of the critical activities of the critical path have been reached STOP as you cannot compress further the project duration. Note: if there are more than 1...