Qt - network crashing problem?

1. Draw Network Diagram and find out Critical Path and its duration.

2.Calculate Cost Slope of all the activity.

3. From Critical path, select Critical activity having least cost slope and crash that activity to full extent provided the critical path does not loose its status.

4.Repeat the above, if critical path duration equals with other path then select then common activity and crash it to the possible extent, but ensure that always original critical path does not loose it status in any crashing.

5.stop the crashing if, crashing cost exceeds the indirect cost or all the activities in the critical path has been crashed.

Thanks for helping me