Perhaps the most challenging concept for many companies was that of working with suppliers as partners. Buyers who spent their lives playing one supplier off against others and switching from one to another to save pennies heard that their Japanese counterparts single-sourced in nearly all cases. What is more, large corporations such as Toyota sent out their own specialists in manufacturing improvement to help their suppliers. Where savings were identified then benefits would be shared amicably.

The most readily-visible consequence of this was better service from the company’s suppliers. If we were working together on agreed plans and the supplier could arrange activities based around a long-term relationships then we might avoid a major problem that plagued us in the West – that just as we played off suppliers against each other, they played off their customers. They never knew what demand they may get so they sought more orders than they could, in reality, fulfil. They then reacted to screams and shortages and tried not to fall out too often with each customer. All of this meant all customers holding safety stock to cope with the repeated failures.

Partnership approach brought other benefits – if we worked as true partners then we would not need to spend so much effort in continuously expediting. We could leave behind this ludicrous situation where we had to keep asking «is that order going to be on time?». We could also expect our suppliers to warn us of problems in advance. If their key piece of plant broke down and they told us now of the impact this might have in a week or two, then we could set our own plans to work around the problem.

Variety was recognised for its cost in that it complicated the manufacturing process. A sunroof on every Toyota Corolla was not only a marketing trick but a practical manufacturing improvement as having to make two different types of roof and two different types of headlining introduced potential problems.

One point which we all understood was that our overall cycle times for our product dictated the level of work-in-progress (WIP). If we have an average lead time of four weeks for the components going through our welding department, then we will have an average WIP level of four weeks’ worth of production.

The Japanese had addressed this in a number of ways, primarily in a fundamental redesign of factory layout and process flow. We learned that rather than have one area of the plant for presses, another full of lathes, another drills, and so on, they had switched to «focussed factories» where each area of the plant made a particular type of component. The unit making drive shafts had saws, followed by milling, turning, drilling and so on. These focussed units then brought the opportunity for multi-skilling and teamwork which helped to provide for productivity improvements – as well as significantly reducing the movement of materials through the factory.