Mixed strategy is a planning strategy that uses two or more controllable variables to set a feasible production rate. However, this strategy is very challenging for the operations manager. Finding the optimal plan is not always possible and methods can vary. a. Graphical methods in aggregate planning are techniques that work with a few variables at a time to allow planners to compare projected demand with existing capacity. It is a trial and error approach which does not guarantee optimization, but requires computations. In this approach even the clerical staff can follow the steps: (1) determine the demand in each period, (2) determine capacity for regular time. overtime and subcontracting. (3) find labor costs, hiring and layoff costs, and inventory holding costs, (4) consider company policies that may apply to workers, and (5) develop alternative plan and examine their total costs. b. Mathematical approaches such as transportation method of linear programming produce an optimal plan for minimizing costs. c. Management coefficients model, a formal model built around a manager's experience and performance. d. The linear decision rule that attempts to specify an optimum production rate and workforce level over a specific period. e. Scheduling by simulation which uses a search procedure to look for the minimum cost combination of values for workforce size and production rate.