Continuing on Kanban…
Post by Bill Kirchherr
Last week I lead a webinar on Pull Kanban and while we were able to cover a lot of ground in 30 minutes, the subject is nothing if not complex, so I wanted to take this opportunity to follow-up.
One of the questions posed was in regards to whether a pull Kanban system was an inventory control system… My answer is no because more importantly, it is a scheduling system, allowing immediate acknowledgement to demand requiring a quick response. The key is to produce only quality parts, produced only when needed, and to the exact quantity withdrawn by the production process. When done properly, it is a level loaded synchronized flow, balanced to the customer demand. This produces simplified scheduling, shorter lead times, reduced work in process and an optimized usage of space.
However, the pull system must be easy to understand and convenient to use. As discussed during the webinar, the positioning of the supermarket is critical. When we can’t flow, we strategically position supermarkets to buffer the inconsistencies in the process or demand. This could be due to a variety of issues such as long lead times, machine reliability, quality issues or constraints.
Due to the short time of the webinar, I was not able to address the critical aspect of monitoring the system once it is implemented. A successful system should have requirements being met with low levels of inventory, replenishing with small lot sizes with the ability to react quickly. If you are on the verge of not meeting customer demand or unable to maintain supermarkets, either there is a change in demand or performance, or the original data was incorrect. It is important to get to the root cause. It may be as simple as the customer not processing the kanban at the desired rate.
In addition to the obvious benefits of reduced lead time and reduction in work in process, is an increase in employee involvement. The employee is an integral part of the Kanban system. Employee ownership in decision making, scheduling and workplace organization should optimize flow and improve communication. Inventory management also becomes an easier task; instead of managing pieces or counting pieces, you just have to manage the number of signals.
The end result of any improvement activity should be that the desired outcome has been achieved. A pull system tells us what to produce, when to produce it and how much to produce based on actual customer need or consumption.
Please share your success stories on implementing and maintaining a pull/kanban system – I am always looking for examples of successful systems. CONNSTEP uses Kanban Made Simple in our training programs – we recommend this book.