The precedence diagram for the problem above is attached. See the definition of a precedence diagram and the probability calculations below.
A precedence diagram is an optical or graphical representation tool that displays a project's activities.
Recall that:
z = (Specified Time - Path's mean)/Path's Standard Deviation.
Hence for z₂₁
(21 − 20.5)/1.118 = 0.447 ≈ 0.45.
Hence the probability is: P(Z<0.45) =0.6736
(21 − 21.5)/1.344 = −0.3721 ≈ −0.37
Hence the probability is: P(Z<-.37) = 0.3557
(21 − 19.5)/.726 = 2.066 ≈ 2.07
Hence the probability is: P(Z<2.07) = 0.9808
Following through on the above, the project will be finished in less than 21 days is given as:
P = 0.23499920921
P ≈ 0.2350
Learn more about Probability at:
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