A Proposed Performance Audit Methodology for Lean 6S Applications

6S is a lean manufacturing technique based on continuous improvement philosophy, which is comprised of six steps: sort, set in order, shine, standardize, sustain and occupational safety. Different audit methods have been proposed in the literature for auditing 6S application performance; however, there is no study showing the validity of checklists and scoring systems of these audit methods. In addition, checklist items related to occupational safety are considered to be superficial. On the other hand, it is a well-known fact that improvements in the occupational safety have productivity-enhancing effects, and similarly, productivity-enhancing activities lead to improvements in occupational health and safety (OHS) issues. The Elmeri method is a OHS method based on checklists, whose performance has been scientifically validated for OHS supervision. In this study, a simple and fast performance audit method based on the Elmeri method has been proposed, which can be used in the manufacturing industry. The proposed method is called 6S-Integrated Performance Audit Method (6SE). The 6SE method presents a new checklist with a total of 40 items of observation rules, 18 of which are from the Elmeri method, 22 of which are derived fom the 6S literature. The application of the 6SE method was carried out in 5 workshops in a large-scale furniture company in Kirikkkale. The 6SE and Elmeri indices of the factory were calculated on the basis of the collected observation data both on a general basis and on a workshop basis; performances were evaluated according to these index values. Also, the effect of the 6S improvement studies on the aforementioned indices has been analyzed and interpreted. The results showed that the proposed 6SE method is capable of determining the level of continuous improvement in the workshop.