Construction Engineering

Crashing

Shortening a project schedule by adding resources to critical activities, cheapest per day first.

Crashing buys time with money. Each activity’s cost slope is the added cost per day saved, (crash cost − normal cost)/(normal duration − crash duration). Only critical activities shorten the project, so the cheapest critical activity is crashed first, one day at a time.

After every step the paths must be rechecked. Once two paths are equally long, every further day has to come off both, either through an activity they share or through one on each — and the combined cost may exceed that of an activity that looked expensive earlier.

How much of the FE Civil exam is Construction Engineering?