Task 4 I. A1. Expected Completion Time ECT is derived using the formula which obviously gives more weight to the “probable” time estimate:Where a = Optimistic time b = Probable time to complete m = Pessimistic time Before allowing for concurrent activities. those that can proceed on parallel tracks, as it were, ECT for the entire project is shown by Table 1 (overleaf) below as 68 ? weeks:Table 1: First Estimate of ECT

a m b Calculation Expected Time to Complete (weeks) Task

A 2 3 4 (2+(4×3)+4)/6 3 B 5 6 13 (5+(4×6)+13)/6 7 C 3 4 8 (3+(4×4)+8)/6 4.5 D 10 11 15 (10+(4×11)+15)/6 11.5 E 4 5 6 (4+(4×5)+6)/6 5 F 8 10 12 (8+(4×10)+12)/6 10 G 4 6 11 (4+(4×6)+11)/6 6.5 H 8 10 18 (8+(4×10)+18)/6 11 I 3 6 12 (3+(4×6)+12)/6 6.5 J 2 3 7 (2+(4×3)+7)/6 3.5 TOTAL

68.5But the fact is, there are many possibilities for concurrent project activity. Task B, for instance, can be triggered by project start and has no start-to-finish link with Task A. Task D itself does not depend on tasks A and C being completed; it can proceed as soon as B is done. When one runs through all the concurrent stages, net elapsed time can really collapse to 35 weeks (Table 2 below). Given ECT = ES + t, as well, Table 3 (overleaf) displays the calculations and outcomes which compress project completion to 30 weeks.Table 2: ECT Based on “Probable Time to Complete” and Employing Forward Pass Task Preceding Activity Probable Time to Complete (weeks) Earliest Start Earliest Finish START

A START 3 0 3 B START 6 0 6 C A 4 3 7 D B 11 6 17 E C 5 7 12 F B 10 6 16 G F 6 16 22 H D,E 10 17 27 I G 6 22 28 J H,I 3 28 31 END

TOTAL 64

31II. A1a. Schedule Variance Conceding a degree of uncertainty for each task and employing the formula for variance of activity time:Where a = optimistic time and b =…