SCHEDULING OF REPETITIVE PROJECTS WITH COST OPTIMIZATION

Existing dynamic programming formulations are capable of identifying, from a set of possible alternatives, the optimum crew size for each ac tivity in a repetitive project. The optimization criterion of these fo rmulations is, however, limited to the minimization of the overall dur ation of the project. While this may lead to the minimization of the i ndirect cost of the project, it does not guarantee its overall minimum cost. The objective of this paper is to present a model that incorpor ates cost as an important decision variable in the optimization proces s. The model utilizes dynamic programming and performs the solution in two stages: first a forward process to identify local minimum conditi ons, and then a backward process to ensure an overall minimum state. I n the first stage, a process similar to that used in time-cost trade-o ff analysis is employed, and a simple scanning and selecting process i s used in the second stage. An example project from the literature is analyzed in order to demonstrate the use of the model and its validity , and illustrate the significance of cost as a decision variable in th e optimization process.