JIT-Jidoka (Autonomation)

Hello friends

This is my third article in series of Toyota Production System and JIT. The earlier two ones were Toyota Production System and Kanban.

I was recently writing the research paper on 'What are the true enablers of JIT?', and one of the true enabler under consideration was 'The enhanced information exchange between supplier and buyer'. In order to prove it to be enabler I presented the following discussion.

Another evidence, strengthening the notion of usage of information systems in JIT from the very start is Jidoka or Autonomation. This is a system, where quality assurance is made a prerequisite of JIT implementation. This is a information system, where if the quality of the product comes out to be bad for considerable number of consecutive times, then the signal is sent, which shuts down all the lines which act as customer or supplier to the defects producing station. This is done to maintain the continuous flow in JIT. If, the signal is not sent, then due to shortage of input material the customer lines will run without actually producing anything. Similarly, if the signal is not sent, then the supplier lines will keep on working leading to overproducing the output product, which the customer station (the defect producing station) would not be able to accept. And above all this is done to bring the immediate focus of everybody on the defects. This focus leads to the immediate remedy of the problem most of the times.

Now, how this signal is generated. In the traditional automobile environment, the operator or the authorized person on the defect producing station pulls the hanging rope (above the station). This rope is connected to all the lines. And pulling the rope from any point leads to the shut down of all the connected lines.

The method of generating signal was modified to electronic means, when the rope was replaced by a button available on all the stations. This button, when pressed via common electrical supply shuts down all the connecting production lines. And immediately, the Andon board, with all the stations labeled on it, starts indicating that problem is occurring on a particular station. And recently, with the improvement of Internet and Information Technology this is done by use of sophisticated electronics and software.

This system was enhanced and implemented to an extent, that even the supplier and customer plants were sometimes stopped by the signal.