Gantt and Pert Exercises

Gantt and Pert Exercises
1) Shipways boatyard undertakes spring refits on cabin cruisers and yachts. In the past, the company has received complaints from customers regarding the time taken to complete the job. Consequently, the M.D. Alan Waters has decided to carry out a critical path analysis on the cabin cruiser refit. The table below gives, for each activity, the duration, immediate preceding activities and the number of staff required.
Task Description Duration (Days) Preceding Activities Staff
A Bring craft up slipway 1 — 2
B Overhaul seacocks 3 A 1
C Scrape and prepare hull 7 A 2
D Paint hull 4 C 1
E Remove engine 2 A 3
F Overhaul engine 16 E 1
G Clean and paint engine 3 E 1
H Refit engine 3 F and G 3
I Apply Antifouling paint 2 D and H 2
J Refloat 1 B and I 2
a) Draw an activity-on-arrow and determine how long the refit will take. What are the critical activities and the slack time of the non-critical activities have?
b) Draw a Gantt chart and Staff Profile for the project. What is the maximum number of staff required and when is this required?
c) Unfortunately, there is only four staff available during the period of the refit. Using your Gantt chart and/or the Staff Profile, re-schedule the activities so that no more than four staff will be required.
2) A building project consists of nine activities, details of which are given below:
Activity Duration (Weeks) Preceding Activities Cash Required (£000)
A 4 — 20
B 2 A 40
C 1 A 20
D 3 B and C 10
E 1 B and D 9
F 2 D 18
G 4 E and F 7
H 2 A 5
I 1 G and H 19
a) Draw an activity-on-arrow for the project and for each activity calculate the earliest and latest start and finish times and the clack times for the non-critical activities.
b) How long will the project take to be completed?
c) If the activities start at their earliest possible times, draw a Gantt chart and determine the maximum amount of cash that will be required in any one week.
d) If cash flow problems meant that a maximum of £60000 was available in any one week, could the project still be completed in the time you calculated in a)?