System Toyota Of Production: TPS or STOP?

Another way to think about lean manufacturing is that it is a system of stopping: no more waste, variation or overburden, just the value the customer wants at the right speed, quality and cost. The classic TPS house comprised of the pillars of JIT and jidoka (built in quality + autonomation) on the foundation of heijunka (production smoothing) with cornerstones of standard work (takt, work sequence, standard WIP) and kaizen (continuous improvement). In the lean management system there are various supporting philosophies, tools, systems and subsystems to enable high performance across all metrics by following this model. These are all in fact ways of stopping behaviors that detract from high performance. Here is the TPS house as a system of stopping:

Stop making the same thing. The foundation of the TPS house is heijunka or production smoothing, which is to produce every needed product every cycle (daily). This is done by reducing changeover times, working with the production planning, sales and customer organizations to break orders from large quantities into smaller ones that more closely reflect the actual consumption, thereby reducing the bull whip effect not only within the site but across the supply chain.

Stop work until signaled: The JIT pillar, comprised of takt time, one piece flow, downstream pull prevents overproduction and the misuse of resources such as labor, materials, energy and capacity by synchronizing supply and demand locally and across the enterprise. The one piece pull creates processes which are balanced within a line, cell or other team-based work method one-by-one, with the rule to stop until the next process signals demand for the next unit of work. In the case of physically disconnected processes the kanban acts as the information link to signal work.

Stop if you can’t follow the standard. The jidoka pillar, whether auto-stop built in as autonomation / intelligent automation into machines or the manual andon lamp and cord used to call for help, are ways of allowing the process to alert the area supervision to potential problems early and often. This is no to say simplistically “stop the line” but rather create a system that proactively seeks out minor problems during the course of work before they become line-stoppers. This requires first stabilizing endemic issues and assigning the resources needed at the line to address sporadic stoppages.

Stop thinking. Kaizen is one of the cornerstones of the Toyota Production System philosophy and operating model. Kaizen is following the PDCA (Plan, Do, Check, Act) cycle in making changes. Put in place the 60% solution so that you can check the “beta” version of your idea or countermeasure through a practical experiment or trial. Stop your brainstorming and start your trystorming. Kaizen is learning by doing, and more simple but great ideas come from moving hands and feet than from just moving lips or tapping on a keyboard.

Stop following the standard. Standardized work… must be followed, should it not? Only for a month or so at a time, according to Taiichi Ohno, sensei of senseis. The standard must be rewritten at least every month, based on improvements. Of course it needs to be followed day to day but not blindly accepted as “the best possible way” but only “the best way we know at the moment” and that moment should pass quickly.

Thank you for reading. But now please stop reading and go help someone make things better.

---