Project Management Dr. Everette S. Gardner, Jr.

Project Management Dr. Everette S. Gardner, Jr.

PERT / CPM advantages 1. Disciplined planning 2. Realistic objectives 3. Unambiguous communication 4. Allows management by exception of critical tasks Project Management 2

Drawing networks Activities on nodes (AoN) A B Activities on arrows (AoA) A B Dummy activities – In AoA, any 2 events in network can be directly connected to only one activity. w Wrong: 11 w x y 12 Project Management 11 x Right: Dummy 13 12 y 3

Drawing networks (cont.) Many computer programs require one initial event and one terminal event A x 98 1 0 100 2 y B Dummy start 99 Dummy stop What’s wrong with this? 10 L 12 J K 11 Project Management 4

Drawing exercise 1 Activity A B C D E F G Predecessors A A B,C C D E,F Draw this format in AoN format. Repeat in AoA format. Project Management 5

Drawing exercise 2 Activity A B C D E F G Predecessors A,B A,B C C,D F Project Management 6

Scheduling calculations: 1. Forward pass – Start each activity as early as possible. ES Max. EF of immediate predecessors EF ES Task time 2. Backward pass – Work backward from the project completion time in step 1, starting each activity as late as possible. LS LF – Task time LF Min. LS of immediate successors 3. Compute slack times. Slack LS – ES or LF – EF Project Management 7

Black Lagoon project Work breakdown table: Preceding Succeeding tasks Description B Edit script Casting Special effects Build sets 4 Horror scenes Other scenes Previews Edit film Task # 1 2 3 2 5 6 7 8 Days 2 1 2 1 1 3 3 1 2 1 5 5 Project2 Management A 6 4 4 6 tasks B A 3 5 5 4 6 7 8 8 8

Black Lagoon project (cont.) Precedence diagram: #1 (2 days) Edit script #2 (1 day) Casting #3 (2 days) Special effects #4 (2 days) Build sets #5 (3 days) Horror scenes #7 (1 Day) Previews #6 (1 day) Other scenes #8 (2 days) Edit film Project Management 9

Time-cost tradeoffs Activity direct costs Direct cost Crash – Activity fully expedited Normal – No expediting Time Project Management 10

Time-cost tradeoffs (cont.) Project direct costs Direct cost All activities crashed All activities normal Time Project Management 11

Time-cost tradeoffs (cont.) Project total costs Total cost Total cost Indirect cost (overhead) Direct cost Time Project Management 12

Network crashing problem Consider the following AoA network: Duration 0 4 70 9 30 1 50 6 4 7 150 Cost slope 5 90 8 80 2 4 200 5 3 3 ** ** Activity 3-5 cannot be expedited The duration of each task is shown above the arrows. The cost slope for each task is shown below the arrows. The initial critical path is 0-1-2-4-5 @ 22 days. The initial cost is 3,050. Project Management 13

Network crashing problem (cont.) Cost and time data are: Activity 0-1 0-2 1-2 1-4 2-3 2-4 3-5 4-5 Normal Crash Time Cost Time Cost 4 days 210 3 days 280 8 400 6 560 6 500 4 600 9 540 7 600 4 500 1 1,100 5 150 4 240 3 150 3 150 7 600 6 750 3,050 4,280 Cost Slope 70 80 50 30 200 90 ** 150 ** Activity 3-5 cannot be expedited Project Management 14

Network crashing problem (cont.) Develop schedules ranging from 22 to 17 days for this project. Record the critical paths and total costs below: Schedule Duration 22 Critical Path(s) 0-1-2-4-5 Total Cost 3,100 21 20 19 18 17 Project Management 15