Design of a Lean Capacity Optimization Strategy for Machines Under No Mixing Policies

Abstract

Manufacturing systems operating under fixed batch sizes and strict no-mixing requirements often experience capacity losses due to misalignment between production order quantities and machine cycle capacity. This research examines a three-machine manufacturing system where recurring idle machine cycles lead to underutilized assets, increased lead times, and elevated work-in-process levels. Using the Define, Measure, Analyze, Improve, Control (DMAIC) methodology, the study identifies traceability limitations within machine cycles as the primary root cause of capacity loss. A traceability-based feeding system is developed that enables multiple production orders to be processed within the same cycle while maintaining compliance with quality, process, and documentation requirements. The solution incorporates uniquely identified trays, enhanced documentation, and 5S-based preparation to eliminate idle machine cycles without changing batch sizes or adding equipment. The results demonstrate that hidden capacity can be unlocked through process redesign and improved traceability in constrained manufacturing environments.