course: project management
PROJECT MANAGEMENT Crashing Example You are the project manager of the software installation project in the tables below. You would like to find the minimum cost-schedule for your project. Assume that partial crashing is allowed. What would be your minimum target completion time and total project cost? TIME ESTIMATES (WEEKS) FOR SOFTWARE INSTALLATION PROJECT Activity Immediate Predecessors Optimistic Most Likely Pessimistic s 13 A 8 10 12 D AB 2 4 B 3 D 10 EF 2 G 7 CF 9 7 A B 3 3 8 E F G H 1 1 6 1 $ 6 6 5 11 3 12 12 COST DATA FOR SOFTWARE INSTALLATION PROJECT Immediate Normal Cost Crash Time Crash Cost Activity Predecessors (S) (weeks) (5) 2.000 3 4,000 B 5.000 7 8,000 A 10.000 8 12.000 D AB 3,000 3 7,000 E B 4,000 2 5.000 F D 8,000 6 14,000 G EF 2.000 2 2.000 H G 6,000 5 9.000 1 CF 7.000 7 15.000 SOLUTION: TIME ESTIMATES (WEEKS) FOR SOFTWARE INSTALLATION PROJECT Activity Expected Time (62) (weeks) Variance, (0%) A 5 0.444 B 8 2.778 10 0.444 D 4 0.444 E 0.444 F 9.5 0.694 G 2 0.111 7.5 1.361 1 9 1.000 Project Network, Forward Pass, Backward Pass, and Slacks SC 7 01 215 3 12 12 215 O 1295215 Start 12 0 88 11 215235 31 0 8 10.5 185 235 0 235 3 215 22.5 235 7511 Crash Times and Costs Estimates Normal Time Activity (weeks) 5 B 8 C 10 D 4 E 3 F 9.5 G 2 H 7.5 1 9 Total Cost Normal Cost ($) 2,000.00 5.000.00 10,000.00 3,000.00 4,000.00 8,000.00 2.000.00 6,000.00 7.000.00 47.000.00 Crash Time weeks) 3 7 8 3 2 6 2 S 7 Crash Cost 5) 4,000.00 8.000.00 12.000.00 7,000.00 5.000.00 14,000.00 2.000.00 9,000.00 15.000.00 Maximum Crash Time 2 1 2 1 1 3.5 0 2.5 2 Crash Cost Per Week 1.000,00 3,000.00 1.000.00 4.000.00 1.000.00 1.714.29 NA 1,200.00 4,000.00 Initial Solution Project Duration Normal Cost Crash Cost (Cumulative) 31 weeks $47.000.00 0 Crashing Project Activities Initial Duration After Crashing n/a n/a Crashed Activity Crashed Time Paths ACI ADFI ADFGH BDFI BDFGH BEGH 24.0 27.5 28.0 30.5 31.0 20.5 Project Costs PROJECT MANAGEMENT Crashing Example You are the project manager of the software installation project in the tables below. You would like to find the minimum cost-schedule for your project. Assume that partial crashing is allowed. What would be your minimum target completion time and total project cost? TIME ESTIMATES (WEEKS) FOR SOFTWARE INSTALLATION PROJECT Activity Immediate Predecessors Optimistic Most Likely Pessimistic s 13 A 8 10 12 D AB 2 4 B 3 D 10 EF 2 G 7 CF 9 7 A B 3 3 8 E F G H 1 1 6 1 $ 6 6 5 11 3 12 12 COST DATA FOR SOFTWARE INSTALLATION PROJECT Immediate Normal Cost Crash Time Crash Cost Activity Predecessors (S) (weeks) (5) 2.000 3 4,000 B 5.000 7 8,000 A 10.000 8 12.000 D AB 3,000 3 7,000 E B 4,000 2 5.000 F D 8,000 6 14,000 G EF 2.000 2 2.000 H G 6,000 5 9.000 1 CF 7.000 7 15.000 SOLUTION: TIME ESTIMATES (WEEKS) FOR SOFTWARE INSTALLATION PROJECT Activity Expected Time (62) (weeks) Variance, (0%) A 5 0.444 B 8 2.778 10 0.444 D 4 0.444 E 0.444 F 9.5 0.694 G 2 0.111 7.5 1.361 1 9 1.000 Project Network, Forward Pass, Backward Pass, and Slacks SC 7 01 215 3 12 12 215 O 1295215 Start 12 0 88 11 215235 31 0 8 10.5 185 235 0 235 3 215 22.5 235 7511 Crash Times and Costs Estimates Normal Time Activity (weeks) 5 B 8 C 10 D 4 E 3 F 9.5 G 2 H 7.5 1 9 Total Cost Normal Cost ($) 2,000.00 5.000.00 10,000.00 3,000.00 4,000.00 8,000.00 2.000.00 6,000.00 7.000.00 47.000.00 Crash Time weeks) 3 7 8 3 2 6 2 S 7 Crash Cost 5) 4,000.00 8.000.00 12.000.00 7,000.00 5.000.00 14,000.00 2.000.00 9,000.00 15.000.00 Maximum Crash Time 2 1 2 1 1 3.5 0 2.5 2 Crash Cost Per Week 1.000,00 3,000.00 1.000.00 4.000.00 1.000.00 1.714.29 NA 1,200.00 4,000.00 Initial Solution Project Duration Normal Cost Crash Cost (Cumulative) 31 weeks $47.000.00 0 Crashing Project Activities Initial Duration After Crashing n/a n/a Crashed Activity Crashed Time Paths ACI ADFI ADFGH BDFI BDFGH BEGH 24.0 27.5 28.0 30.5 31.0 20.5 Project Costs
