November 11, 2021 by The refining industry has struggled to execute large, highly complex turnarounds on budget and on schedule. Our data indicate that more than two-thirds of turnarounds exceed their planned cost and schedule by 10 percent or have a trip after startup. Forty percent of turnarounds experience a cost overrun or schedule delay of more than 30 percent. The turnaround work scope is the most critical item related to performance outcomes, as it is the foundation for cost, schedule, and plant reliability. Minimizing the amount of scope and the level of scope growth during the turnaround execution window is the primary driver of competiveness. This paper discusses the challenges to scope control, describes a methodology for benchmarking scope, and illustrates how this methodology can be used to benchmark scope and provide early and reliable forecasts of labor hours and costs.