Parameters

t: unit processing time for a part s: setup time required for any batch processed c1: unit inventory holding cost for finished part per unit per time unit c2: unit inventory holding cost for the work in process part per unit per time unit cs: unit setup cost cPM: unit preventive maintenance cost cr: unit restoration cost (corrective cost) cw: unit rework cost per part for nonconforming part tPM: time interval for preventive maintenance (in constant assumption) β: shape parameter for the Weibull distribution α: scale parameter for the Weibull distribution p1: probability of defect part on in-control state p2: probability of defect part on out-of-control state q: number of parts to be processed d: an order delivery time (a common due date)
