Personnel scheduling with flexishift models

The concept of personnel scheduling when alternative work hours are permitted is presented in this article. The concept, called Flexshifts, schedules 6-, 8-, and 10-hour shifts against a 12- and 24-hour daily demand profile. Using the concept, required shifts can then be offered to the labor staff allowing each individual to select those shifts that best fit their personal plans. Alternatively, certain shifts can be guaranteed to key employees. Case studies reported in this paper indicate many advantages to allowing workers to opt for different start times, to select their days off and to create non-standard workweeks from predefined sets of 6-, 8- and 10-hour days. Computerized timekeeping systems make this flexibility manageable. Personnel scheduling algorithms such as the one presented here make the planning of Flexshift easy. The formulation presented here utilizes linear programming. Tests of the L.P. Flexshift model on 42 data sets of 12-hour days showed an average savings in labor of 24.2% when compared to an L.P. model of the traditional 8-hour work shift. For a 24-hour work pattern, that formulation outperformed a published heuristic for 8-hour shifts by reducing average idle time from 13.9 to 5.4%.