is not easy to start for implementation. The researchers used the Pareto Rule 80:20 [16]
of total history purchasing of suppliers within 1 year to begin with. And then each supplier has requested to
isolate the forecasting model in each product list. The warehouse management is applied by re-layouting with the
concept of storage separating supplier. The reasons of re-layouting the warehouse are, first, to count inventory on
hand and, second, to reduce inventory damaged cost.
The inventory model is called with minimum stock and maximum stock in period ordered [17]. The inventory
carrying is considered to level stock (Low, Medium, and High). It is obvious that if the inventory carrying is less
than safety stock then there is a back log. If the inventory carrying is greater than safety stock then there is an
over-inventory. If the inventory is carrying is equal to safety stock, there is else medium inventory (as shown in
Figure 1). Moreover, it can be known how long the over-inventory holds on without purchasing. These can be
made possible by using Microsoft Excel. The formulations of calculation are shown below.