INTEGRATED APPLICATION OF LEAN TOOLS FOR PROCESS OPTIMIZATION IN SME MANUFACTURING: A CASE STUDY OF REFRIGERATION EQUIPMENT PRODUCTION

Abstract

Small and medium-sized enterprises (SMEs) often operate with resource constraints, high product variety, and informal processes that hinder systematic efficiency improvements. This paper presents a single-case study of an SME that manufactures customized refrigeration aggregates for industrial cooling applications and applies an integrated set of Lean tools for process optimization. The research follows an action-oriented approach and combines SIPOC (Suppliers-Inputs-Process-Outputs -Customers), process flowcharting, value stream mapping, eight-waste analysis, Pareto analysis, Ishikawa diagrams, and 5S-based proposals. The current-state Value Stream Mapping (VSM) reveals a total non-value-added time of 24 days and 170 minutes and a value-added time of 615 minutes, with major wastes arising from waiting, motion, inventory accumulation, and rework. Pareto analysis shows that waiting for chassis components and unnecessary operator movement account for more than 60% of recorded disruptions, while the Ishikawa diagram highlights structural causes linked to manpower, methods, materials, machinery, measurement, and the working environment. A future-state VSM, built on targeted improvements, reduces non-value-added time (NVAT) to 15 days and 170 minutes and increases value-added time (VAT) to 650 minutes, and an ideal-state design suggests further reductions to 6 days and 140 minutes. The paper demonstrates that a coordinated application of Lean tools can provide SMEs in specialized manufacturing sectors, such as refrigeration equipment production, with a practical roadmap for diagnosing inefficiencies and designing coherent, high-impact improvement strategies.