Application of Lean Six Sigma for Sample Checking Audit Procedure Process Improvement in the Apparel Sector in Sri Lanka

Abstract

Lean Six Sigma has become a well-known tool to improve operational excellence in manufacturing as well as service organisations. Lean Six Sigma generates a significant positive contribution to an organisation’s performance in improving processes by reducing cycle time and waste in the process. This study is focused on real practical scenario of Hela Intimates (Pvt) Ltd, Narammala which is having lengthier time periods for the Acceptable Quality Level (AQL) Audit procedure than the Standard Operating Procedure time periods. This is a qualitative and quantitative research in nature. The main research objective of this study is to improve the process quality by reducing the current cycle time using Lean Six Sigma of the Acceptable Quality Level audit process of the sample checking process at Hela Clothing Ltd Narrmmala. Both primary and secondary data are used to reach the study objectives. Two thousand three hundred and twenty-six AQL audits in the month of June are considered for the sample. Cluster sampling method under Probability sampling method is used to draw the sample and the direct observation method is used to gather AQL audit cycle time. In addition to that, three auditors are interviewed in order to identify the waste types in the AQL process. To analyse the data, Lean Methodology and DMAIC methodology which is used under Six Sigma is used. Under this methodology Process control chart, Non-value-added activities calculations, descriptive statistics and Perato chart are considered to analyse the data. To analyse the interview data, the contents and pattern matching method is used. The results of the analysis revealed that the present AQL Audit process is stable and yet the process can be improved further. Based on its AQL audit procedure, cycle time is reduced to 35 minutes from 45 minutes and it is a 22% process improvement from the current process by using Lean Six Sigma methodology. Therefore, it clearly evident that Lean Six Sigma can be used as a process improvement tool for apparel sector in order to meet customers’ requirements.