“Just In Time” manufacturing, like many concepts in the industry, has been around for 80 years or so. Henry Ford used an early version when he developed the first true production line and he didn’t want lots of money tied up in inventory. He had to bear in mind poor delivery methods which meant that he needed more inventory in storage than his production lines needed. One option he had was to have as many components made on-site or locally to reduce the time for delivery.
After World War 2, Toyota sent some people to look at the Ford system and they took some ideas from the production line, however they observed how one American supermarket chain worked and this gave them the basis for the Toyota Production System (TPS). This work was done in conjunction with an American, William Derning who had relocated to Japan after the war. He was a statistician who had helped the US industry make improvements for the war effort and he went to work to rebuild the industry in a totally smashed country.
The TPS is based on Muri, Mura and Muda or overburden, inconsistency and waste. The 7 possible points of waste are: over-production, motion (of the operator or machine), waiting (of the operator or machine), conveyance, the build process, inventory (raw materials) and correction (rework or scrap).
What this has done for many manufacturing companies is to look at the most efficient way of building products with the minimum of waste. The system gives the production line workers the ownership of their section and they have the ability to stop the line when an error occurs but also they are empowered to input into the process design so that errors can be eliminated.
In some respects “Just In Time” production is just common sense, however when companies try and get products out quickly they often start to cut corners and the process bogs down, or they try and build based on political interference that causes costs to rise sharply. Proper adherence to JIT helps to smooth out the processes and reduces costs. Reducing costs should help to increase profits – provided other costs remain the same.
We can all learn from the Toyota Production System in our working lives – we often just need recognition that there is a problem in the first place!