Evaluating Construction Work Disruptions Using Resilient Short-Interval Scheduling: A Case Study

摘要

Construction job sites are fluid, and unpredictable obstacles occur almost every day. These obstacles disrupt the original time schedule causing delays, reduced labor productivity, and extra costs for manpower and materials. One solution is to build resilience into the scheduling process to withstand the disruptions. With an existing short-interval schedule data set for electrical case projects, we identify the causes of the disruptions and their associated schedule impacts-the number of hours not worked as scheduled (NWAS) which involves both the time loss due to obstacles like absenteeism and the time spent on other tasks not scheduled. A disrupted schedule becomes resilient when the construction workers, instead of sitting idle, are reassigned to other tasks they otherwise were not expecting. Moreover, knowing the hours NWAS caused by different obstacles allows for decision-making about which obstacles require more attention and immediate action than others. To that end, we frame the resilient scheduling problem in a conceptual decision framework and suggest a measure of resilience in a short interval schedule using recoverable time and lost time. This measure of resilience is illustrated further with a case study and a sensitivity analysis showing the uncertainty of the schedule impact due to the disruptions.