Scrap loss reduction using the 5-whys analysis

Purpose - This paper seeks to document an approach to reduce scrap losses using the root cause analysis technique in a lean manufacturing environment.Design methodology approach - The study uses lean manufacturing root cause problem solving (RCPS) technique. The study starts with the collection phase, followed by the analysis phase and ends with the solution phase. Supporting data are presented using a Pareto chart to prioritise wastage in order to be more focused for improvement. The Toyota Production System's 5-whys analysis is performed to analyse the cause of wastages, to formulate and implement corrective actions.Findings - The application of the 5-whys analysis in a manufacturing industry (XYZ Corporation) provides a fact-based and structured approach to problem identification and correction that not only reduces, but also totally eliminates defects. Corrective action has permanently eliminated the top defect, which is the "last piece material scratch" and this results in zero scrap thereafter. In this study it was also proven that with sound understanding of manufacturing coupled with possible solutions using the 5-whys analysis the authors were not only able to eliminate waste, but also to do it with zero-cost.Originality value - The approach documented in the paper can be extended to other areas in the manufacturing industry to help improve overall equipment efficiency, breakdown, time loss, customer complaints, etc.