Productivity Improvements in the Electrical Cabinet of the New Refrigeration Unit

Abstract

Thermo King is a leading company in the manufacture of transport temperature control systems. In the factory Reftrans S.A., refrigeration units for vans are designed and manufactured. The plant has 4 production cells where a wide range of units are assembled, approximately 24,000 per year. With the new launch of the main competitor and with the demanding annual goals of reducing costs, it was decided to start a project to modernize the current V800 that provides 8,000 W of cooling capacity and add to the catalog a new machine called V1000 that provides 10,000 W. The main objective of this project is to design the wiring harness and the electrical cabinet (optimal components placement) of the new units V800 and V1000, in order to increase the productivity of the plant. It has been increased in two ways: reducing the manufacturing time and reducing the material cost of the new wiring harness. In order to achieve this aim, different methods related to the industrial organization have been applied. First of all, the optimal assembly order has been defined for the new cabinet design. From the operations list, the assembly times of the old V800 cabinet have been compared with the new one. The objective of reducing this time by 25% has been achieved. Using the Helgeson & Birnie Algorithm, the balance and the workstations have been defined for the entire V800/V1000 production line, both for work at maximum capacity and medium capacity. Next, the procurement strategy has been defined and the appropriate cabling supplier has been selected using the Kraljic matrix and the Analytic Hierarchy Process (AHP). The purchasing and stocking strategy of the wiring harness have also been planned using the Material Requirements Planning (MRP). Finally, an economic analysis has been carried out, in which the objective of reducing 15,000€ per year the material cost of the wiring harness has been achieved. After calculating the NPV and the IRR, it can be stated that the investment is profitable and with a return period of 2.84 years.