This paper introduces a practice-oriented and field-tested approach to measure and evaluate volume and mix flexibility of a lean production system. After an introductory literature review revealing and classifying various types of flexibility as well as models to determine the flexibility of production systems, the most important flexibility types – volume and mix flexibility – are identified. Existing approaches for volume and mix flexibility evaluation are hard to implement in practice for different reasons: They are often bound to specific constraints or require extensive and complex input parameters. Additionally a lot of these models neglect the actual demand for flexibility.
Lean production systems strive for a reduction of throughput times by eliminating non-value-adding work. In a perfectly lean and flexible production system responding to volatile demands, time gaps between customer demand dates and production dates would be removed completely for every single order. The model designed therefore uses the capacity-weighted difference of demand and corresponding production in a restricted time period for each product variant in relation to the total capacity demand.