“…A few examples of such studies include: a single item inventory system with a non-stationary demand process in a single stage production inventory system (Graves, 1999), a periodic review stochastic inventory system (Chan and Song, 2003), determination of lot size and order level for a single item, single stage inventory model with a deterministic time-dependent demand (Dave, 1989), a single item and single stage inventory system with stochastic demand in a periodic review where the system must order either none, or at least as much, as a minimum order quantity (Kiesmüller, De Kok, and Dabia, 2011) and to analyse three inventory models; a replenishment batching policy, a production batching policy, and an integrated replenishment/production batching policy (Rau and OuYang, 2007).…”