A TIME-COST TRADE-OFF MODEL WITH RESOURCE CONSIDERATION USING GENETICALGORITHM

A genetic algorithm (GA)-based model to deal with time-cost trade-off problems is presented. The traditional algorithms assume the unlimited availability of resources. Instead, the proposed model allows for res ource constraints. Accordingly, the trade-off is considered in terms o f the level of resources to be deployed for each activity. At the same time the model schedules the starts of the activities in order to opt imize the objective function. The activity starts is a significant fac tor in the case of non-uniform available profile. The GA searches both spaces of resource utilization and activity starts to determine the o ptimal schedule that conforms to the resource available profile. Altho ugh, in principle, this has the potential of a combinatorial explosion . earlier work suggests that the GA-based model can be applied to larg er networks without appearing to suffer from this problem. Allowing th e project manager to think in terms of resource utilization makes this approach consistent with resource allocation problems, and more pragm atic and appealing. The model can also be used to solve conventional t ime-cost trade-off problems by a simple modification of the objective function. Numerical examples are used to illustrate the working of the model. The examples include a case of varying resource available prof ile.