A heuristic approach for measuring criticality in Activity networks

Concepts of critical path and critical activities are very familiar with project managers and are widely recognized as fundamental in project planning and control. However, their use is reduced in practice. In case of activity duration stochastic variability each activity could be critical with a given probability, since the critical path is not univocally defined and each path has a non zero probability to be critical. In this case, the analysis is focused on the estimation of the mean project duration and on its variability; the importance of an activity is measured by its criticality index. Many indices are proposed in the scientific literature to cope with such a problem. However, a general approach to measure the influence of activity durations variability on the project duration is not yet available. In this paper the authors propose an approach to contribute to overcome the above mentioned limit. The approach is based on response surface methodology. A numerical example outlines the approach capability in identifying efficiently project activities most affecting project duration variability.