Note the design or layout of the process in a factory. In the past, in this factory every machine out of five of the booth lathes, milling machines, and driller placed side by side: one machine is held by a worker, for example one only holds one turner lathe.
According to the Toyota production system ,The engine layout would be reformed to expedite the flow of production.Therefore, every worker will hold three types of machines. For example, one worker will hold a lathe, a milling machine, and a drilling machine at the same time. This system is called double-handling process (multi-process holding). In other words, single-function workers, a concept that was applicable at the Toyota factory, now a dual-function workers.