Question: Consider a Component X, one unit of which is used in every 5th Stapler (e.g., X could be a cartridge used to hold the staples). The average lead-time (= wait time in queue + production time) for one container of Component X is one week. The container size for X is 20 units; so each time Component X's kanban authorizes production 20 units of X are produced. A 20% minimum safety stock is desired to compensate for uncertainties; this means that the desired target inventory is at least 1.20 times the work-in-process inventory level computed using only the average data provided above (without uncertainties). Estimate the number of kanban cards required for Component X.