Project schedule with alternative activities and relationships

The complexity arising from planning large-scale construction projects often requires representation and evaluation of alternative programs. however,prevailing schedule tools seldom consider and explicitly represent the alternative activities and relationships for further evaluation. moreover,how to deal with the temporal relationships associated with alternative activities are also inadequately explored. a mixed integer linear programming model is developed to represent the alternative construction programs,and then the concept of criticality of activities is extended to incorporate the alternative relationships. the computation example and the case study demonstrate that project period and the optimal sequence of activities can be derived using the developed model.