... service level. In fact, the demand is greater than the total capacity of the set of machines; hence there rises a necessity of subcontracting to complete the missing demand. In addition, we consider that the unit cost of subcontracting is a variable depending on the quantity subcontracted. As a result, we...

... which has to satisfy a random demand during a finite horizon given a required service level. Motived by our recently work in Hajej et al. (2015) , we proposed a mathematical model to study the opportunity provided by the extended warranty for the lessee as well as for the lessor under...