Shorten the Critical Path at the Least Cost:

The easiest way to proceed is to start with the normal schedule, find the critical path, and decrease the path time by one day using the lowest-cost activity. Then recomputed and find the new critical path and reduce it by one day also. Repeat this process until the time of completion is satisfactory, or until there may be no further reduction in the project completion time. Table illustrates the reduction of the network one day at a time.

Table: Reducing the Project Completion Time One Day at a Time