The Luddites of Lean
Most people reading this will assume that the Luddites in the title are those who have not embraced the Lean manufacturing message, but in fact the Luddites are the many Lean practitioners who ignore the benefits technology can bring in creating an even Leaner environment. To try and understand why these practitioners are seen as Luddites, a simple review of Lean Manufacturing will help.
The Basics of Lean Manufacturing
Most Lean practitioners will take you through a multi-step process towards your Lean goal: SKU (Stock Keeping Unit) Analysis.
Analyse the production volume created by each of the products (SKUs) that you make. Typically, it is claimed, about 6% of your SKUs will make up 50% of the production volume, so you concentrate on these items first.
Value Chain: Build Value Chain Maps for your high volume products and remove non value added activities (booking in and out of stores, unnecessary movements, etc.) from the process.
Flow Production: Create flow production for the high volume products by dedicating resources to them and move to a fixed sequence, fixed quantity production schedule. The aim is to make every SKU on every cycle of the schedule.
Process Improvement: Work to improve the production further, typically by reducing setup times so you can reduce the quantities on each cycle, thus making the cycles faster. As your process improves you can move to a fixed sequence, variable quantity schedule.
Single Piece Flow: Ultimately you make your process agile enough to enable single piece flow (batch quantity of one), allowing you to implement a variable sequence, variable quantity schedule.
What have you achieved?
You have taken non value added activities out of the process, and you have made the process more agile by reducing setup times so you can now make exactly what the customer wants, but at what expense?
You have created production cells by dedicating resources to particular products or product groups. The benefits of cellular production are well documented, but so is the lack of flexibility it brings. For example, demand increases for one product that overloads its cell, but it is difficult to use the capacity of other cells to help out because of the artificial ‘walls’ you have created between the cells.
No account has been taken of the margins produced by your products. Lower volume products with variable demand may actually contribute more to your bottom line that the high volume products, yet you gain no help in managing the production of these products. Both of these issues are caused by the segregation of your products and the creation of production cells, which raises the question:
Why are Production Cells Required for Lean?
To answer this question we need to look at the origins of Lean Manufacturing. The original concepts of eliminating the waste caused by non value added tasks, setups, etc. can be traced back some decades, with the Toyota Production System often held up as the classical example. In those days MRP was the only IT based production control system in town, and the simplistic scheduling built into MRP was incapable of handling a very agile process.
With no IT solution available the early Lean practitioners looked to what we would now call Visual Production Control (VPC), typically based on kanbans and supermarkets, but again this technique could not cope with a large, flexible and agile production facility. So the practitioners back then took the obvious step, they simplified the production control problem by building product based cells, so VPC would work.
The term ‘counter intuitive’ is often used by Lean practitioners to describe some of the logic that drives their advice, but the most counter intuitive thing they promote is the idea that in the 21st century a very simple, some would say primitive, visual production control system is still the best, if not the only, way to control your production.
The value of computer software
In virtually every field of human endeavour, computers have enabled us to control processes more accurately and efficiently, and a few examples that spring to mind are:
Cars: My first car had a 1098cc engine that produced 48bhp giving a top speed of about 70 mph, and it did about 30mpg. My current car had a three litre V6 engine that produced well over 200bhp, it is much bigger, faster and heavier than my first one, but it also does about 30mpg. How? Mostly by using a computerised engine management system of the type that has made all our cars much more efficient over the last 30 years or so.
Aircraft: The USAF Stealth fighter and bomber are designed to be ‘invisible’ to radar but their resulting shape makes them aerodynamically unstable. If they had been built 30 years ago with a simple non-computerised flight control system, the pilots would not have been able to fly them.
Manufacturing: Most new production equipment is computer controlled, which makes it more flexible, agile, accurate, repeatable, etc.
But, despite these advances, we are repeatedly told by our Lean practitioners that IT has no place in our production control system, and we should use techniques that could have been implemented in the 19th century, never mind the 21st. It is this dedication to antiquated production control techniques that has earned some Lean practitioners the title ‘The Luddites of Lean’.
It is also interesting to note that if you buy a new piece of computer controlled production equipment, you are then expected to shackle its flexibility by putting in a cell that only makes a few products. Yet by using IT, particularly Advanced Planning and Scheduling (APS) software, the Lean philosophy can be pursued towards its ultimate objective, making only what the customer ordered, when the customer wants it. In other words Make to Order (MTO). So how would you implement an APS based Lean project?
The Basics of APS Based Lean Manufacturing
Install APS: As well as the direct improvement in the visibility and control of your production process, your APS will also allow you to analyse your process to determine where you need to concentrate your efforts to achieve the flexibility and agility you desire.
Process Improvement: Work to continuously improve your production by removing non value added activities, reducing setup times, etc. so you can reduce the quantities in each batch. As your process agility improves you can make smaller and smaller batches, but always maintain the variable sequence that gives you true flexibility.
Make To Order: Ultimately you make your process agile enough to enable MTO (batch quantity of one), allowing you to implement a variable sequence, variable quantity schedule across all your manufacturing resources.
Right from the start of this process you are also empowering your planner to make scheduling decisions against your company-wide Key Performance Indicators (KPIs). For example, this week you may have to take the utilisation hit by making small bathes so you can meet your delivery targets, but next week you may be able to dynamically aggregate some smaller batches to improve utilisation because the delivery profile is different. Plus, because you have retained the flexibility to make any product on any capable equipment, you can use capacity from all your capable resources to satisfy orders for high margin products with irregular demand.
