Kanban is a highly visual method for managing workflow, inventory, and more. Kanban encourages the use of visual indicators to improve the flow and efficiency of production, making it an ideal method for manufacturers of physical goods. One of the most familiar tools used in Kanban manufacturing is called a 2 bin Kanban system.

Learn how 2 bin Kanban systems work, their pros and cons, and whether they might be right for your organization.

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What is a 2 Bin Kanban System?

The 2 bin system is, quite literally, a system which uses two physical bins to manage inventory, usually of small but critical parts (such as fasteners and class C components). It’s a simple pull system, where the parts are supplied by two rotating containers.

The system works simply by supplying workers with two plastic storage bins, which contain inventory that they pull from to fill orders or to provide supplies to various departments. The speed at which the individual items are used will determine how many of the items are placed in the bins.

The workers pull from one bin until it is empty, and then they switch to the second bin while at the same time placing an order to replenish the items in the first bin. The number of items required to replenish the first bin is predetermined, so that there is little risk of running low on stock (which could slow down production).

Pros and “Kans” of a 2 Bin Kanban System

The 2 bin Kanban system seems foolproof, but there are several elements that must be considered to make it effective. For example, the time it takes to reach the bottom of a bin must be longer than the time needed to order and receive the replacement inventory. If not, the second bin could become empty before the replacement stock arrives.

The goal of any 2 bin system is to have enough inventory to continuously produce outputs without having too much surplus inventory. To ensure that this happens, many companies choose to only use the 2 bin method for small parts that are needed in small volumes that they know they can order and receive quickly. If they can do this, manufacturers often find great success using 2 bin systems.

Although 2 bin Kanban systems seem easy, they can become incredibly complex when scaled across hundreds and hundreds of bins.

Often, if employees find that they are always cutting it close with inventory replacements, they’ll add more parts to each bin. Seems logical, right?

But actually, it’s counter-intuitive – adding more parts to each bin will further delay the ordering process, slowing the entire system down. This is where 2 bin systems often fail, so it’s important, before implementing any sort of inventory management process, to do the math and ensure that the proposed system will effectively meet the needs of your supply chain.

Is a 2 Bin Kanban System Right for Your Process?

If your team handles a significant volume of small, easily accessible parts, a 2 bin system could help establish an efficient and effective system of inventory management. If, however, you are dealing with larger, more expensive parts or parts that require significant lead times, a different method might be a better fit. It’s likely that you deal with both, and might need to create a hybrid system that combines both 2 bin systems and more sophisticated methods of inventory management.

Before implementing any sort of inventory management system, it’s important to understand the specific needs and considerations affecting your supply chain. Many factors, such as fluctuating demand, lot quantities, minimum orders and other variables can all impact the exact order requirements to keep your Kanban system running smoothly.