9 Project Management

Project Management: 

Project Management Dr. Everette S. Gardner, Jr.

PERT / CPM advantages: 

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

Drawing networks: 

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. Wrong: Right: 11 12 w x y 11 12 13 w x y Dummy

Drawing networks (cont.): 

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

Drawing exercise 1: 

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

Drawing exercise 2: 

Drawing exercise 2 Activity Predecessors A - B - C A,B D A,B E C F C,D G F

Scheduling calculations:: 

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

Black Lagoon project: 

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

Black Lagoon project (cont.): 

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

Time-cost tradeoffs: 

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

Time-cost tradeoffs (cont.): 

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

Time-cost tradeoffs (cont.): 

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

Network crashing problem: 

Network crashing problem Consider the following AoA network: ** 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. 0 1 5 4 2 3 4 70 9 30 8 80 6 50 5 90 4 200 7 150 3 ** Duration Cost slope

Network crashing problem (cont.): 

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

Network crashing problem (cont.): 

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