Question

Based on the following table, please create a diagram. Also please calculate and show the ES, EF, LS, LF times along with the slack for each activity using the critical path methodology.

Required completion is 30 weeks.

Activity	Estimated Time (Weeks)	Actual Finish Time (Weeks)	Immediate Predecessor
A	6	6
B	5	8
C	7	11	a
D	9	9	A
E	4		C,D
F	5		B,D
G	3		B
H	10		E,F,G

Based on your completed network diagram please answer the following questions.

1. What is the critical path for the project at the end of the planning process?
2. At the end of the planning process, can the project meet its required completion date? What is its estimated completion date?
3. Before applying the actual finish times, which activities pose the greatest risk to the project and why?
4. After applying the actual finish time, identify the activity(s) that should be concentrating on to get the project back on schedule?
5. What tools would you use to bring it back on schedule once you apply the actuals?

Answer 1

Acitvity	ES	EF	LS	LF	slack
A	0	6	0	6	0
B	0	5	12	17	12
C	6	13	9	16	3
D	6	15	6	15	0
E	15	19	16	20	1
F	15	20	15	20	0
g	5	8	17	20	12
H	20	30	20	30	0

critical path is ADFH with duration of 30 according to the plan. However, the activities B and C are late by 3 and 4 days respectively. Since C has a slack of 3, and if it gets late by 4 days, it will affect the completion of the project, for which the new critical path will be ACEH with duration of 31, and the project will be delayed by 1 period. B has slack of 12, hence the lateness of 2 days will not affect the project in any way.

Before knowing actual timings, the activities on critical path which are A,D, F and H pose the greatest risk becausedelay in anyone of them causes direct delay to the project duration. The risk is less with the other activities which have slacks.

E and H are the activities which needs to be addressed to bring the project on schedule, by trying to reduce their time somehow by one day ( either of the activities) This can be done by either speeding up the tasks by adding more workers or increasing the working time of resources.