PROBLEM FORMULATION
To crash a project, the project needs to be completed within an earlier deadline (less than 21 days in the example problem), and at minimum cost. We first briefly describe the logic of the problem for project crashing. The problem is generally formulated according to the following guidelines.
Min total project cost
Subject to:
(1) Project completion time an earlier deadline;
(2) Number of days can be shortened for each activity maximum available days for crashing for the activity;
(3) Non-negative decision variables, which are the number of days each activity will be crashed.