As described in his 1988 book, “Toyota Production System: Beyond Large-Scale Production,” his concept was based on a Pull approach to manufacturing, where processes and actions are triggered by actual events in the real world – such as a machine failure or the need for a part on the production line. This was opposed to the old way of production, called Push, where processes are guided more rigidly by plans and schedules.
In theory, Mr. Ohno proposed 2 pillars that formed the foundation of TPS. These are JIT (Just-In-Time) and autonomation (Jidoka). Both pillars are based on the concept of a Pull signal triggering a business process based on actual, real-time information.
JIT requires production activities to be carried out at just the right time in order to minimize any queuing of jobs or materials, which are considered waste. For example, the completion of a product downstream automatically triggers the start of an upstream assembly operation, so there is no unnecessary queuing of work-in-process materials.
Autonomation is about automating the business process of stopping machines and correcting problems based on a real-time response to the unplanned event of machine malfunction. This can prevent production of defective parts, eliminate overproduction and avoid delays. Autonomation relieves the workers from the need to continuously judge whether the operation of the machine is normal. The workers are then only engaged when there is an alert for a problem and hence can simultaneously supervise several machines to achieve better cost-effectiveness.
So why was Mr. Ohno ahead of his time?
Because the technology to fully enable his vision didn’t exist in 1988. Pull approach requires the real-time flow of data among all the steps of manufacturing, so that processes and timing can be tightly synchronized. Back then, with only mainframe batch-processing and rudimentary event sensing available, Taiichi Ohno sought to implement his system without the use of computers. And while he couldn’t fully realize his vision, he was able to succeed sufficiently to revolutionize production at Toyota and at manufacturing facilities around the world.
But that was then. Today, the necessary computer technology not only exists, but it is increasingly being used by manufacturers and their suppliers to explore the usage of real-time information in a complex production and supply chain. That means the full potential of the “The Toyota-Style Information System,” as Ohno envisioned it, is finally beginning to be realized today. And, it is making a very large impact on manufacturing enterprises.