Minimization of WIP Inventory Cost at CNC Machining Centers through Assignment of m Serial Machines and Transfer Batch Size Reduction
Chaznin R. Muhammad, A. Harits Nu-man, Nisa Shofia
Teknik Industri, Universitas Islam Bandung
Jl. Tamansari No.1 Bandung 40116
Abstract
CNC Machining Center is a type of CNC machine that can does several processes simultaneously. In some cases, this machine is often single used to make a product through several production stages, from raw material to end product. The reason for using a single machine is to avoid material handling time from one production stage on one machine to the next on another machine. In the case of batch production, the use of a single machine will cause the products flow time to be long which will certainly increase the cost of work in process (WIP) inventory. This research was conducted to reduce the cost of WIP inventory of motorcycle spare parts on the CNC Machining Center. Minimization of WIP inventory cost is done through two steps. Step 1 is to allocate three production stages to three serial CNC Machining Centers. Stage 2 is determining the transfer batch size (10 units) is smaller than the production batch size (50 units). The results of this study indicate that the WIP inventory cost for the use of a single machine is Rp. 2.150,250, while the WIP inventory cost for three serial machines is Rp. 202,100.
Keywords: CNC Machining Center, batch production, WIP inventory, production batch, transfer batch.
Topic: Industrial Engineering