Line balancing is one of the most important components of mass and large-scale production systems. The primary objective of this study is to assign tasks to the workstations, so that the manpower and machines can perform the assigned tasks with a balanced loading. This calls for uniform rate of manufacturing as well as decrease in the work in process (WIP) inventory.

In this study, Ranked Position Weight (RPW) method has been applied to Medium Voltage (MV) line of a manufacturing industry assembling Pix Cassette Panels. In the outset of the study, data was collected from workstations of existing assembly line through direct observations and recording the process. Operation Work Standards (OWS) and Work Breakdown Structures (WBS) have been made for workstations to understand the complete process and detailed descriptions of each activity. Then standard time for each WBS has been determined using time study. The takt time of existing assembly line is found as 120 minutes. It is also found that the line is running with a very low efficiency of just 48.96% and have a high balance delays of around 51%. This shows that more than 50% of time is idle due to inappropriate assignment on work stations in the existing line.  The industry has an average demand of 100 panels per month. However, only 74 panels are assembled at average despite of using additional 90 hours as overtime per month. With the help of Ranked Position Weight (RPW) method, the takt time has reduced to 100 minutes by balancing workloads on each workstation. The newly designed assembly line is running with the efficiency of 97.30 % with a balance delay of just 2.7 %. The number of work stations are reduced from 7 to 6. It has a capacity to assemble 100 panels per month with lesser labors and machines. The overtime has been reduced to zero. Additional to management expenses, it will save around PKR 400,000 per month as operating and labor costs. Ranked Position Weight (RPW) method suggests very high line efficiency and therefore, strongly recommend to apply to various production lines such as process, textile etc.  

Keywords: Ranked Position Weight (RPW) Method, Line Balancing (LB), Operation Work Standard (OWS), Work Breakdown Structure (WBS), Takt Time, Line Efficiency (LE), and Balance Delays (BD).