On evaluating the impact of flexibility enhancing strategies on the performance of nurse schedules.

Hospitals develop nurse schedules that cover a period of 4-6 weeks and are posted several weeks in advance. Once posted, changes to the schedule require voluntary participation by the nurses, making it difficult for hospitals to respond to changes in nursing needs and availability of nurses. At the same time, nursing needs' forecasts developed several weeks in advance are often wrong. In each hospital setting, there may exist several promising strategies to enhance scheduling flexibility and reduce the mismatch between the nursing needs and the availability of nurses. However, methodologies to evaluate such strategies, before testing them in expensive pilot implementation, do not exist. We demonstrate how such evaluations can be carried out using historical data. Furthermore, we demonstrate the use of our approach by evaluating the benefits of a strategy where nurses are divided into two cohorts and schedules are phase shifted for the two cohorts. Staggering schedules allows nursing unit managers to benefit from more frequent updating of needs' assessments without having to change work rules. Upon applying our approach to data from a large urban hospital, we discovered that in this example staggering did not improve the performance of nurse schedules. We discuss possible reasons for this result, its implications for hospital managers, and other potential uses of our approach.