Lean RFS (Repetitive Flexible Supply) -- A Missing Part of Lean Journeys?

Ian Glenday and Rick Sather recently published a very interesting book titled Lean RFS (Repetitive Flexible Supply): Putting the Pieces Together. I recently had an email exchange with both authors, and I had the chance to ask them about two key assertions that appear in the book:

1. “Existing planning processes used by most companies are fundamentally flawed.”

2. “The original foundation of the Toyota Production System is the least understood aspect of Lean, yet is crucially important.”

These are bold – some would say controversial – statements, and I asked them directly how they justify them. I’m reprinting their entire answer here:

In most companies, the weekly plan or schedule is different every week and then usually changes resulting in firefighting. This makes continuous improvement, agreed standards, and root cause resolution of problems very difficult to achieve and, more importantly, sustain. Planning is based on “economic order quantity” or batch logic that uses three main data sources – the sales forecast, actual production, and inventory levels. If any of these have changed since the plan was last calculated then one gets a different plan. For the plan not to change would require 100% perfect data – and that is NEVER going to happen. Forecasts will be wrong, production will make more or less than the plan, and as for 100% inventory accuracy – who has that?

There is an alternative planning logic – often referred to as flow. It is seen as the logic of Lean and is usually described as focused on achieving greater responsiveness to demand. However, this aspect of flow is the last two steps in a five step process Toyota followed. The initial steps focused on creating stability -- an essential foundation for sustainable continuous improvement, root cause resolution, and the following of standards. The term Toyota now uses to describe this is “heijunka.” It was, however, originally called “patterned production” as it created a fixed repeating plan. This seems impossible to achieve when demand is seen as variable. In steps 1 to 3, this repeating plan gets faster and faster resulting in shorter runs and more change-overs. This flies in the face of conventional thinking on how to improve performance. Using examples and quantified results from Kimberly-Clark and other companies, we show how it can be done and how levels of performance improvement previously thought impossible were achieved.

Is the weekly plan ever changed in your company? Have you ever heard of “patterned production”? In his foreword to the book, Professor Daniel Jones makes the following comment: “This book is the missing link in many Lean journeys.” What do you think of that powerful statement?