9.1: Schedule Compression
Notes
Video 9.2: Fast Tracking
Video 9.3: Laddering
Fill in the missing task names below after watching the video on Laddering.
Assuming the time for all tasks are 1 week (Dig Ditch A, Dig Ditch B, Cover Ditch A, etc) and if laddering was not used, the project would take 9 weeks. With laddering, how long would it take?
Video 9.4: Crashing a Project
Check Your Knowledge
Questions: Reducing Project Duration
Exercise 1
You are given the following data about project tasks, network, and crash times/costs. Calculate the cost of the project at all time durations until you can no longer crash the project. All times are in days.
ID | Direct Costs | Slope | Maximum Crash Time | |||
Normal | Crash | |||||
Time | Cost | Time | Cost | |||
A | 5 | $500 | 4 | $600 | $100 | 1 |
B | 10 | $1,200 | 6 | $2,000 | $200 | 4 |
C | 13 | $3,600 | 11 | $4,800 | $600 | 2 |
D | 13 | $300 | 11 | $600 | $150 | 2 |
E | 5 | $1,000 | 4 | $1,400 | $400 | 1 |
F | 10 | $2,400 | 8 | $5,400 | $1,500 | 2 |
G | 5 | $700 | 5 | $700 | $0 | 0 |
Exercise 1.B: Initial Network
Calculate the critical path(s) and the direct costs of this project:
Duration:
Critical Path 2:
Duration:
Project Duration:
Total Direct Costs:
Exercise 1.C: Crashing
If possible, calculate the critical path(s) and the costs of crashing this project by 1 day:
Duration:
Critical Path 2:
Duration:
Project Duration:
Normal Duration Direct Costs:
Additional Costs of Crashing:
Total Cost at this time period:
Repeat these calculations until the project can no longer be crashed.
Exercise 1.D: Total Costs
Record the direct costs that you calculated at each duration in the table below. Calculate the total project costs (figuring in the $500 per day incentive to finish early) at the various time periods.
Initial Dur | -1 | -2 | -3 | -4 | -5 | -6 | -7 | |
Project Duration | ||||||||
Total Direct Costs | ||||||||
Incentives ($500 per day that project is delivered early) | – | |||||||
TOTAL COSTS |
What is the optimum time period in terms of total cost?
Exercise 2
You are given the following data about the project tasks, network, and crash times/costs.
Calculate the cost of the project at all time durations until you can no longer crash the project.
ID | Direct costs | Slope | Maximum Crash Time | |||
Normal | Crash | |||||
Time | Cost | Time | Cost | |||
A | 10 | $5,000 | 10 | $5,000 | $0 | 0 |
B | 12 | $1,200 | 11 | $1,300 | $100 | 1 |
C | 11 | $3,600 | 9 | $4,800 | $600 | 2 |
D | 5 | $300 | 4 | $600 | $300 | 1 |
E | 8 | $1,000 | 6 | $2,000 | $500 | 2 |
F | 9 | $2,400 | 7 | $5,400 | $1,500 | 2 |
G | 8 | $700 | 7 | $1,000 | $300 | 1 |
Exercise 2.B: Initial Network
Calculate the critical path(s) and the direct costs of this project:
Project Duration:
Total Direct Costs:
Exercise 2.C: Crashing
If possible, calculate the critical path(s) and the costs of crashing this project by 1 day:
Project Duration:
Normal Duration Direct Costs:
Additional Costs of Crashing:
Total Cost at this time period:
Repeat these calculations until the project can no longer be crashed.
Exercise 2.D: Total Costs
Record the direct costs that you calculated at each duration in the table below. Calculate the total project costs (figuring in indirect costs) at the various time periods.
Initial Dur | -1 | -2 | -3 | -4 | -5 | -6 | -7 | |
Project Duration | ||||||||
Total Direct Costs | ||||||||
Indirect Costs | $3,000 | $2,500 | $2,000 | $1,500 | $1,000 | $500 | $250 | $0 |
TOTAL COSTS |
What is the optimum time period in terms of total cost?