TPS is a set of tools and philosophies that model the perfect world. What some organizations, their management team and Lean consultants forget is that we need to strive for our ideal world. The perfect world is out there and whenever I am training anyone on TPS I teach them about the perfect world however, I always tell them that they will never make it to the perfect world. It is a model that we need to understand and strive for but we should understand it is unattainable. If anyone ever tells me they are operating in the true model of TPS and have made it to that perfect world I would have to laugh.
In talking to a VP of Manufacturing who had attempted to implement lean with the help of a consultant in the past, they agreed with this concept. The company, a furniture manufacturer, had short lead-time (5 days or less between customer request and shipping), high mix (400 different products and components) and a very unstable volume (one day they would have 6 trailers of deliveries, the next they would have less than a quarter of a 45 foot trailer). Each machine that the component went through would have a set-up time in the region of 30 minutes with a cycle time of 10 to 30 seconds and each component may go through 5 or 6 machines with around15 components per assembly not your ideal scenario for single piece pull at takt time.
The consultant had trained both the companys leadership and the operators on the floor. He had explained the philosophies of Takt, Flow and Pull and was driving the manufacturing company towards a JIT environment. It would appear that his drive was towards the perfect world with little thought given to the consequences on the rest of the organization or how they would make this leap. Previously the environment was batch & queue, running orders of 300 parts through a machine in order to minimize the set-up time cost per part and running one or two different parts on that machine each day. The consultant pushed the company towards batches of 25 to allow them to be able to process at a higher velocity and increase the number of different parts made per day. Great you might think .we are aimed at the principles of JIT and utilizing some of the principle of Heijunka. Once they had been able to bring the batch size down to 25 the plan was to reduce it further and further and further until they were at single piece flow. Unfortunately this blinkered approach caused costs to ramp up significantly and very soon the VP of Manufacturing had to say stop, this is not helping our business it is hurting it!! It sounded like the consultant knew the direction he should be taking the company but hadnt considered the best way to get there, perhaps some SMED would have been the better first step?
The consultant took a very rigid position and told the Executive VP and President of the company that the VP of Manufacturing was a dinosaur and had to go because he didnt understand the principles of lean & JIT and was so ingrained in the batch and queue system that the company would never change while he was in place. Fortunately the senior management took the side of the VP of Mfg and the consultant was the one to go. Even today though, the senior management will tell you that they tried lean but werent able to make it work. I saw many places where some of the lean principles (Jidoka, pokayoke, standard work, visual management etc) had been applied to the facility.
What both the consultant and the senior management have missed is that link between ideal and perfect worlds. We should understand the perfect world and hold it up as a light to guide us but we need to temper that with a modicum of reality to find our ideal world.