Relationship Between Variants and Inventory Under Consideration of the Replenishment Time

It is common wisdom that the finished goods inventory increases with the number of variants stored in that inventory. However, to the best of our knowledge, this has never been verified. This paper presents research where this relationship has been analyzed both by applying theory and through analytical simulation. The result shows that this common wisdom is not always true. The number of kanban increases as the customer takt decreases if the customer takt is smaller than the replenishment time. If the customer takt is larger than the replenishment time, a change in the customer takt will not change the required minimum inventory of one. Similar holds true for the number of variants.