Define ‘slack’.

Question

(i) Define ‘slack’.                                                                                                                     5

(ii) A project consists of six activities. The precedence relationship of activities and the three time estimates of completion of activities in days are tabulated below:

Sl. No.	Activity	Immediate Precedent Activity	Estimate Time of Completion (days)
			Optimistic	Pessimistic	Most likely
1 2 3 4 5 6	A B C D E F	- A B A A C,D,E	0.5 1.0 2.0 2.9 1.5 3.0	1.5 3.0 2.0 4.1 4.0 6.0	1.00 2.00 2.00 2.75 1.63 3.75

1. Draw the arrow diagram.
2. Which of the six activities is most uncertain?
3. What is the probability that the project will be completed within 10 days? Refer the SND-chart (Cumulative Distribution Function for the Standard Normal Distribution) attached at the end.