One of the most difficult process in the current production is about preparation. In a pressing process, for example, common sense to determine that cost reduction can be obtained by continuously using one type of mold, thereby allowing the largest lot size and reduce the cost of preparation. However, in a state where the last process has been smooth production and reduce the dosage between the pons and the next line of the body, as a process preceding the pressing need to prepare quickly and frequently. This means changing the type of mold for the press in accordance with various types of products repeatedly ole taken the next process.
During the period 1945 to 1954 in Toyota, preparation times at the presses of about two or three hours. This was reduced to a quarter of an hour in the years 1955-1964, and after 1970, when it fell to just three minutes.
To shorten the preparation time, it is important to meticulously prepare the first mall, the equipment, the next mold, and material needed, and remove mold and malls that have been released after new molds taken care and started the engine running.Preparation phase is called an external preparation. In addition, workers should focus replacement bike molds, jigs, tools, materials da accordance with the details of the next order while the preparation work berhenti.Fase machine is called the preparation internal. the important one is to change as much as possible the external preparation.