Question

Question 7 Activity Of isti Te Mest IketTe Pesi istic Tre Predecessar A 7 10 13 B 13 15 17 A - с 9 18 21 A D 2 4 6 B CD E 8 9 10 Tasks, precedence requirements, and time estimates for a project are shown in the table. What is the expected completion time of the project? Your answer: 32 35 O 38 42

Answer 1

The formula to calculate the expected time of an activity = (O+4M+P)/6.

Where, O = optimistic time

M = Most likely time

P = Pessimistic time

So using the above formula, the expected completion time of each activity are

• For A = [7+(4×10)+13]/6 = (7+40+13)/6 = 60/6 = 10
• For B = [13+(4×15)+17]/6 = (13+60+17)/6 = 90/6 = 15
• For C = [9+(4×18)+21]/6 = (9+72+21)/6 = 102/6 = 17
• For D = [2+(4×4)+6]/6 = (2+16+6)/6 = 24/6 = 4
• For E = [8+(4×9)+10]/6 = (8+36+10)/6 = 54/6 = 9

Now the various paths and their expected completion time of the project are

• A-B-D-E = 10+15+4+9 = 38
• A-C-E = 10+17+9 = 36

So the critical path is A-B-D-E as it has the longest expected completion time of 38

Expected completion time of the project = Completion time of the critical path = 38

So the answer is 38