This paper presents a computer program to perform optimal cost-based design ofX̄charts when multiple assignable causes can shift the process to an out-of-control state. The optimum values of the design parameters, the sample sizen, the sampling intervalh, and the control limits coefficientkare determined by minimizing the function of the expected loss-cost per hour of operationL′.The partial derivative of the loss-cost function with respect tohis set to zero and is solved to obtain the optimum value ofh. A Fibonacci search procedure for the optimum value ofkis nested in another Fibonacci search for the optimum value ofn.