Project Schedule Management Using a Fuzzy Activity Network Considering Resource and Environmental Factors

Abstract

A project is always performed in an environment influenced by resource and environment factors such as equipment, weather, labor skill, materials delivery, management quality and so on. Since these factors affect various activities on the same path in an activity network, activity durations tend to vary together. The variation of these durations affect the path duration and/or the project duration. This paper introduces a new method that incorporates these factors in a fuzzy activity network and provides factor sensitivity information to support efficient project schedule management. This method uses a triangular fuzzy number for the activity duration, and uses the spread of the triangular fuzzy number for the variation in the estimation of the activity duration. Based on the qualitative estimations of the sensitivity of each activity to each factor, the variation in activity duration is distributed to several factor variations (f-variation). Each f-variation is then broken down into more variations based on factor conditions (c-variations), with each c-variation corresponding to a factor condition such as better-than-expected, expected, or worse-than-expected. The effects of resource and environment factors are captured using c-variations under the same factor conditions to compute path and project durations. The proposed method makes it possible to improve the estimation of the path and project durations. The sensitivity of paths to factors can be searched and effectively used to improve project schedule management. Finally, an example is demonstrated, and the results are compared with other methods.