How Many Kanban?
The number of cards or containers is a key issue. Excess cards and inventory encourage sloppy scheduling and a laissez-faire attitude. Insufficient cards adversely affects customers. Several methodologies can determine an optimum level: • Boundary Analysis • Predetermined Formula • Factor Analysis • Computer simulation • Trial & Error In Boundary Analysis, key people mentally step through system operation using Product-Volume and other data. With simplified methods and risk estimates, they put upper and lower limits on the stock. Predetermined formulae are available. Such formulae usually contain “guess” factors and unavailable data. They often apply to specific situations and have limited usefulness. Factor Analysis identifies the various factors that affect stocks. Examples are setup costs, order volatility, quality issues, stockouts consequences and gross volume. Computer Simulation uses specialized software to build a model of the system. The analyst can vary parameters and arrive
