Question 4

Bigwell construction has developed tasks duration and predecessor relationships in the following table for building model houses. The manager has been concerned with the amount of time it took to complete several jobs, some of the company workers are very unreliable. A list of activities and their optimistic completion time, the most likely time and the pessimistic completion time (in days) for a new contract are given in the following table.

Table 1.

Activity	Predecessors	Optimistic (a)	Most Likely (m)	Pessimistic (b)
A	-	1	2	3
B	-	2	3	4
C	A	4	5	6
D	B	8	9	10
E	C,D	2	5	8
F	D	4	5	6
G	E	1	2	3

A. Draw the activity network for this new contract (either AON or AOA). (4 marks) B. Determine the Expected Time and Variance for each activity. (4 marks) C. Show the activity schedule (ES, EF, LS, and LF) as well as slack (in table). (6 marks) D. Determine and state the critical path for this project. This MUST be based on your work in (C.) and not by inspection. (2 marks) E. What are the expected times and variances of the project? (2 marks) F. What is the probability the project will be finished within 20 weeks? (2 marks)