Uncertain Engineering Critical Path Solving Method Based on Interval Number theory

Abstract

Critical path management is an important way for controlling the schedule of an engineering project, it always difficult to describe by a precise manner for the uncertain characteristic. In this paper, the interval number is applied to describe the uncertain characteristic, and a preference indexes λ are introduced to solve the critical path on linear programming problem. Meanwhile, the control priorities of sub-path can be also analyzed by a sensitivity coefficient δ. The result shows that compared with traditional probability methods and other interval critical path studies, the proposed method can improve the precision of the project time control. From the example and the result analysis, traditional probability method can deal with the uncertain problem of the network, but it may optimistically estimate the project duration time, namely, the duration time is underestimating. But interval critical path solving method could give more accurate duration time and critical path, and the proposed method could give more exact result and the calculation procedure is simpler.