Pricing
320/3338–12FE Reference Handbook 10.4 · Construction · CPM crashing
1. Average End Area2. Equipment Production Rate3. CPM Total Float4. Equipment Cycle Time5. Match Factor6. Earned Value Indices7. Swell and Shrinkage8. Labor Productivity9. Crash Cost per Day10. Liquid-Head Form Pressure11. Absolute Volume Mix Yield12. Early/Late Times13. OSHA Excavation Slopes14. Mass-Haul Diagram15. Concrete Quantity Takeoff16. Resource Leveling vs Crashing17. PERT Expected Time and Variance18. Pay Quantities: Bank / Loose / Compacted19. Crane Lift Chart and Tipping20. Wellpoint / Cofferdam Dewatering Head21. Unit-Price Bid and Unbalanced Bids22. Learning Curve

Handbook formula

Crash Cost per Day

The cost slope of shortening an activity. Crash the lowest-slope activity on the current critical path first. Stop when the next crash costs more than the benefit (liquidated damages or bonus) per day.

Direct cost at crash duration
(day)
Normal duration
($/day)
Cost slope

Step-by-step solved example

Activity: normal 10 d / $4,000; crash 7 d / $5,500. Cost per day saved?

1234TF = LS − ES
Crash the cheapest critical activity; recompute the path.

  1. 1. dC

    5500 − 4000 = $1,500.

  2. 2. dT

    10 − 7 = 3 days.

  3. 3. Slope

    c = 1500/3 = $500 / day.

Answer: $500 per day

10 practice questions

0/10 correct

1.Only crash activities that are

2.Prefer the activity with

3.Normal 8 d $2,000; crash 6 d $3,000. c =

4.If two paths become critical, you may need to

5.Indirect project costs usually

6.Crash duration is a

7.A negative cost slope would mean

8.Benefit of $800/day, slopes $400 and $900: crash

9.After crashing, recompute

10.Dummy arrows have