When managers explain why they're searching for a new shift schedule, it usually boils down to one of these three reasons:

Resource Changes

Either the staff size or the group's budget is changing. If the group is getting bigger, there may be opportunities to use the extra capacity to reduce the average weekly hours, boost coverage on one or more shifts, or build relief coverage into the schedule to cover some of the absences. If the group is getting smaller, the average weekly hours of work may have to be increased to maintain the minimum coverage requirements.

Sometimes upper management wants to cut costs but not change the headcount. The group will have to do a cost analysis of overtime in the schedule vs. overtime outside the schedule to determine the best approach. You can read about this here:  http://www.shift-schedule-design.com/Overtime_Issues. The group may also be forced to consider other schedule changes that will lower costs as discussed here:  http://www.shift-schedule-design.com/Cost_Reduction.

New Business Requirements

When the demand for an organization's products or services changes (usually by increasing), this may require them to hire more employees or make more effective use of their current employees. In either case, it's a good time to align the coverage with the workload. We start the schedule design process by evaluating work volumes and the associated coverage requirements by time of day and day of the week. We also consider absence coverage if the resources are adequate.

Employee Satisfaction

When employees search for a new schedule, they are primarily looking for ways to increase the days off and weekends off. When managers cite employee satisfaction as a reason for changing schedules, they hope that the change will reduce absenteeism and employee turnover, or improve productivity and morale issues. Once business requirements are satisfied, we will evaluate solutions that maximize days off and weekends off and, if possible, reduce the need for mandatory overtime.