Variability degrades project performance. Two types of variability may affect a construction schedule, namely, task duration and the availability of resource and information (RI) prerequisites. It is well known that the variability of task duration could delay project completion, however, the effect of RI availability/unavailability on construction schedule needs to be depicted. This paper presents a simulation model which allows studying the effect of RI related variability on construction schedule. Comparisons are made to illustrate the impact of each type of variability as well as the combination of both types of variability. The results suggest that both types of variability should be minimized in order to achieve reliable work plans which is important to reduce project delays and schedule changes.
Variability, Integrated Production Scheduler, Constraints, Reliable plan