A computer system has recently been installed in the accounts department of a manufacturing company. The activities involved in introducing the system are listed below together with their normal durations and costs. It would be possible to shorten the overall project duration by crashing certain activities at extra cost, so the relevant details are also included. In addition, there will be a weekly charge of $7000 to cover overheads. Normal Time Activity Predecessor Normal Cost ($) Crash Time (weeks) Crash Cost (S) (weeks) 3 A 2000 2 7000 6 5000 6 5000 A 8000 19000 B 1500 1500 E A 8 4000 9000 E B 4 3000 7000 G C, D 2 2000 2000 H F 3 3000 9000 a) Determine ES, EF, LS, LF, and slack for each activity. Activity Early Start Early Finish Late Start Late Finish Slack B C D G H b) What is the normal expected duration of the project? What is the critical path? B D 42 1 25 3 2 2