The third element of a lean transformation comes through levelling (or smoothing) demand. It seems counter-intuitive to many people who associate lean with making only what the customer wants, exactly when they want it. This of course is the ultimate goal, but to do straight away, would require an almost infinitely flexible workforce with huge amounts of excess capacity available ‘just in case’. If demand can be levelled in such a way that customer expectations can still be met, there is enormous potential for improving productivity and reducing costs. Below we have briefly detailed some of the tools we regularly use to help clients achieve this
Glenday Sieve / Fixed Repeating Schedule
We often use a technique known as the Glenday Sieve to analyse the true customer demand fluctuations in a business. Our experience shows that in many organisations true demand is often much more stable than organisations think. However, managers in these organisations assume that demand is highly variable and unpredictable. The Glenday Sieve analysis shows whether an organisation has a ‘Green’ stream of products where demand is both predictable and stable. This is often in excess of 70% of the total sales order book, but is hidden by the variation in the remaining 30%. We work with clients to configure their operations, and their planning functions, around the stable 70%. Demand is often so predictable that we can help teams develop a fixed, repeating schedule, that not only meets customer demand but allows a schedule to be built that gives the operations the most efficient way to process demand. This gives control and order to a huge part of the business, allowing resources to be focussed on managing the remaining 30% (and to work on how this remainder can be made more stable).
Heijunka is the Japanese term for Production Levelling or Smoothing. The Heijunka Box is a visual tool that we help teams design that shows in a simple, yet effective way, how a daily schedule can be levelled over the course of a shift or a day. This visual system also gives a level of short-interval control as its easy to see at a glance whether a process is on plan, ahead or behind. Furthermore, it can also be combined with the use of Kanban, so that production flow is controlled between process steps.