Earned duration management control charts: Role of control limit width definition for construction project duration monitoring

The design of control charts refers to the selection of the sample, the sampling interval, and the width of the control limits. The literature on the use of control charts for project monitoring is concerned mainly with the first two parameters, and does not dedicate enough attention to how to determine the width of the control limits. This paper highlighted the relevant role that the appropriate definition of probabilistic control limit width plays in the project control and the performance of the control charts used to monitor the duration of construction projects. The main contribution is the proposal of a two-step simulation approach to set the most appropriate control limit width. The application of the proposed method was presented. Results demonstrated that there is a trade-off between the performance of the control charts and the control effort to investigate the cause of every warning signal. The preferable choice of α is influenced strongly by different project duration targets, risk and uncertainty scenarios estimated in the planning phase, and the team's risk profile.