Lean Manufacturing Analysis: Using WAM and VALSAT to Reduce Waste in the Plastic Sack Finishing Process at PT Surya Plastindo

PT Surya Plastindo is a company that produces plastic sacks. The finishing workstation often encounters various issues, including an excessive number of defective printed products and production quantities consistently exceeding order specifications. This study aims to eliminate waste and implement improvements in the finishing workstation. The lean manufacturing method is suitable for reducing waste at PT Surya Plastindo. The waste elimination process begins with describing the production flow and calculating cycle times for each process, using Value Stream Mapping (VSM) to depict the current state. Subsequently, the Waste Assessment Model (WAM) is employed to weight and rank critical waste. The most critical wastes are further analyzed using value stream mapping tools, with the VALSAT tool selected to map the value flow during production. Finally, a five-why analysis is performed to recommend improvements. According to WAM’s waste weighting calculations, defects (20.76%), motion (18.32%), and overproduction (17.54%) are identified as the most significant wastes. The analysis, combined with discussions with production heads and detailed mapping using VALSAT tools, resulted in three recommendations for improvement: the creation of daily production cards, checklists for printing machines, and plastic sack supports for the printing machines. The implementation of these improvements resulted in a reduction in delays and increased efficiency in plastic sack production.