a nurse scheduling model under real life constraints

background and objectives: in this paper, a real life nurse scheduling model is described based on the conditions in iranian hospitals such as monthly shift rotation, consecutive morning and evening shifts and consecutive evening and night shift.   methods: the developed model considers both hospital constraints and nurses’ preferences. hospital constraints include assigning adequate qualified number of nurses to all working shifts and avoiding inappropriate sequence of nursing shifts. nurses’ preferences include the nurses’ monthly requests and observing the fairness in ratio of work hours, off weekends, night shifts and undesirable shifts. a hybrid of lexicograph and weighted sum method was used to solve the multi objective problem. the objectives were normalized and the importance of the objectives was determined by the analytical hierarchy process method. in this work, new conditions are considered based on customized considerations. the model was evaluated by comparing the computationally determined schedules with manually determined schedules.   findings: comparison of the manually and computationally determined schedules shows the superiority of computer-based method over the traditionally manual method based on the scales of the hospital.   conclusions: the study provides further support for the utility of sophisticated computational method in improving hospital processes, which can ultimately translate into enhanced patient care and hospital performance.