choice of optimum combination of construction machinery using modified advanced programmatic risk analysis and management model

Since the proper use of construction machinery in infrastructure projects is important, it is essential to employ an optimum selection of machinery in these projects. advanced programmatic risk analysis and management model (apram) is one of recently developed methods that can be used for risk analysis and management purposes considering schedule, cost and quality, simultaneously. in this paper, first the apram method is introduced and then modified in order to consider environmental risks. this method can consider potential risks that might occur over the entire life cycle of the project, and can be employed as an efficient decisionsupport tool for construction managers selecting machinery for an infrastructure project where various alternatives might be technically feasible. a case study of three possible combinations of excavation machines is then discussed. all project risks related to cost, time, quality and environment are identified, considering the capital costs which should be spent on each combination. finally, some graphs which are derived from the method are taken into account in order to decrease each combination’s risks and to optimize the selection of excavating machinery. the outcomes highlight the efficiency of the apram model for the optimal selection of machinery in construction projects.