Optimal work breaks in deterministic and probabilistic repetitive projects

An effective way to reduce the duration and cost of projects with repetitive activities is through the relaxation of resource continuity and the introduction of work breaks at strategic points between repetitive project units. This paper describes the problem and introduces the basic concepts for determining the optimal location and duration of work breaks for both deterministic and probabilistic activity durations. The procedure is described in detail and is applied to an example project with 9 activities with probabilistic durations that repeat over 10 similar work units. The solution employs concepts from the Repetitive Scheduling Method (RSM), the Sequence Step Algorithm (SQS-AL), and is modeled in STROBOSCOPE, an activity-based simulation system. Numerical and graphical results explain the process and the underlying time and cost tradeoffs.