Some Key Definitions ET: Estimated Duration TE: Earliest Expected Completion Time TE = Max [ TE (Previous Process) ] + ET (Current Processes) TL: Latest Expected Completion Time: Time in which an activity can be completed without delaying the project TL =Min[ TL (Later Process ) – ET (Later Process) ] SLACK = TL-TE. Zero Slack = Zero Flexibility.
Network Diagram with ET A ET=1 B ET=2 C ET=3 G ET=6 F ET=4 E ET=5 D ET=4 H ET=6 J ET=3 I ET=2
Network Diagram with ET and TE TE= 1 A ET=1 TE = 2 B ET=2 TE = 3 C ET=3 TE = 9 G ET=6 TE= 6 F ET=4 TE = 7 E ET=5 TE= 5 D ET=4 TE = 13 H ET=6 TE= 16 J ET=3 TE = 11 I ET=2 We take the TE from Process E rather than Process D. Because TE(E)> TE (D) We take the TE from Process H rather than Process I or F. Because TE (H) >TE(I)> TE (F) START From HERE
Network Diagram with ET and TE TE= 1 A ET=1 TL = 3 TE = 2 B ET=2 TL = 2* TE = 3 C ET=3 TL = 5TE = 9 G ET=6 TL=11 TE= 6 F ET=4 TL = 13 TE = 7 E ET=5 TL = 7 TE= 5 D ET=4 TL= 7TE = 13 H ET=6 TL = 13 TE= 16 J ET=3 TL = 16 TE = 11 I ET=2 TL = 13 * We take TL from Process E rather that Process F because TL-ET for E is lover that that of F START From HERE
Critical Process and Critical Path TE= 1 A ET=1 TL = 3 TE = 2 B ET=2 TL = 2 TE = 3 C ET=3 TL = 5TE = 9 G ET=6 TL=11 TE= 6 F ET=4 TL = 13 TE = 7 E ET=5 TL = 7 TE= 5 D ET=4 TL= 7 TE = 13 H ET=6 TL = 13 TE= 16 J ET=3 TL = 16 TE = 11 I ET=2 TL = 13 CRITICAL PATH I S B E H J Path comprising of Process where Slack ( TL-TE) = 0
Critical Path: Questions to Ponder upon What is the importance of Critical Path? How will you distribute your resources when you know the critical path? What happens if process within a critical path is delayed?