Two Ways to Kanban

Two Ways to Kanban: Over the next few weeks, we will present a series of models that use Kanbans. Kanbans are "Instruction Cards" that manage the movement of work or items in a process. This model highlights two key uses of Kanbans - managing the number of specific items in a process or managing the total amount of work in a process. 

0. This model has three items: Item 1, Item 2, and Finished Item.

1. Order Rate is variable. Demand for Item 1 changes throughout the model: C(0.75) from time 0 to 25, C(1.25) from time 25 to 75, and C(0.5) from time 75 to 100.

2. Manage the WIP level with the Core Pull Block. The WIP Cap is set to 5 Kanbans. This represents managing the total amount of work in a process using Kanbans.

3. Hold Incoming Orders. Orders that can't fit within the Core Pull WIP cap are held in this Queue Block.

4. The WIP Cap begins at Released Orders and ends at Order Complete. There will be a maximum of 5 items between these two blocks.

5. This section represents managing the quantity of specific items using Kanbans. The Replenishment Pull Block provides Item 2 to the Kit Block and triggers a restock when the supply gets low enough.

Last week, we looked at a "Water Strider" model where the Replenishment Pull block was configured to act like a "Two-Bin" system. In that model, the bin of the two-bin system acted as our Kanban and was used to manage the inventory level of a specific part. We had three parts in that model, each with its own Replenishment Pull block and two bins to act as Kanbans.

This week, our model includes the other use of Kanbans. Using the Core Pull block, we can set the count of Work In Process (WIP) within specific boundaries of a process. In this case, the Kanban represents an allocation of WIP regardless of the item. This example differs from last week when the Kanban represented a specific item.

Note: there is no physical "Kanban" item in the model. Reality would implement the use of Kanbans while the model represents the results of using those Kanbans.