In this section, whilst using Womack and Jones' 5 principles, some liberties have been taken. Some managers are upset by the five principles, believing them not to be feasible within their industry. But this is to miss the point, which is vision: you may not get there within your lifetime, but try - others certainly will.

The starting point is to specify value from the point of view of the customer. This is an established marketing idea (that customers buy results, not products - a clean shirt, not a washing machine). Too often, however, manufacturers tend to give the customers what is convenient for the manufacturer, or deemed economic for the customer. Womack and Jones cite batch-and-queue airline travel, involving long trips to the airport to enable big batch flights which start where you ain't and take you where you don't wanna go, via hubs, and numerous delays much like the aluminium cola can. How often are new product designs undertaken constrained by existing manufacturing facilities rather than by customer requirements? Of course we have to know who is the customer: the final customer, or the next process, or the next company along the chain, or the customer's customer.

Then identify the value stream. This is the sequence of processes all the way from raw material to final customer, or from product concept to market launch. If possible look at the whole supply chain (or probably more accurately the "demand network"). Again, an established idea from TQM / Juran / business processing. You are only as good as the weakest link; supply chains compete, not companies. Think of the three types of action (above), and eliminate the wastes. The value stream should be mapped, and a whole section of this book is devoted to this topic. In mapping, focus horizontally on the item, not vertically on the departmental silo. Track the experiences of the product or customer, not the experiences of the manager or operator. Focus horizontally, not vertically.

The third principle is Flow. Make value flow. If possible use one piece flow. Keep it moving. Avoid batch and queue, or at least continuously reduce them and the obstacles in their way. Try to design according to Stalk and Hout's Golden Rule - never to delay a value adding step by a non value adding (although temporarily necessary) step - try to do such steps in parallel. Flow requires much JIT preparation activity. This includes modular design, product platforms, cells, small machines, changeover reduction, multiskilled operators, supplier partnership, and enablers such as 5S, TPM, and TQ. But the important thing is vision: you have to have in mind a guiding strategy that will move you inexorably towards flow.

Then comes Pull. Having set up the framework for flow, only make as needed. Pull according to customer demand. Pull reduces time and waste. Do not overproduce. Of course, pull needs to take place along the whole demand flow network, not only within a company. So this ultimately implies sharing final customer demands right along the chain. Now of course, in some industries true pull, instant response is not possible - you cannot grow an orange tree overnight to provide a pulled orange drink - but you can pull for several stages back from the customer, and each extension of pull reduces forecast uncertainty.

Finally comes Perfection. Having worked through the previous principles, suddenly now "perfection" seems more possible. Perfection does not mean only quality - it means producing exactly what the customer wants, exactly when (with no delay), at a fair price and with minimum waste. Beware of benchmarking - the real benchmark is zero waste, not what the competitors are doing.

One quickly realises that these five principles are not a sequential, one off procedure, but rather a journey of continuous improvement. Start out today.

Further Reading
James Womack and Daniel Jones, Lean Thinking, published by 'Simon and Schuster', New York, 1996, ISBN 0-684-81035-2