การพัฒนาและฟื้นฟูสภาพเครื่องจักรในโรงปฏิบัติงานเครื่องจักรกล

Abstract

This research studied a machine from five machine shops (one machine for each shop) which are press brake, wire indenting, milling, straightener and sand blasting machine. It was aimed to improve the productivity of those machines by applying retrofit concept along with reverse engineering technique. From the suggestion of expert engineers, all machines were needed to add new technology to their original systems. After that economic decision analysis was made to decide whether retrofitting investment was worthy or not. The analysis showed that Net Present Value (NPV) of each investment in machine was THB 272,748.41, 162,273.75, 52,424.52, 489,200.05 and 301,232.09 respectively. Internal Rate of Return (IRR) of each investment in machine was 152.34%, 47%, 45.02%, 107.86% and 79.49% respectively, which were higher than Minimum Acceptable Rate of Return (MARR) at 7.375%. Payback period of each investment in machine was 0.65, 1.81, 1.88, 0.9 and 1.19 years respectively, which were acceptable by the managers of each factory. Therefore, the investment should be made. The next step was to apply retrofit concept to all machines and then compare the production rate with the original systems. It was found that productivity of each machine had been improved.