Here is an interesting example of Kaizen back in the machine shops of Toyota in the 1950’s. TPS originated in the machine shops of Toyota under the direction of manager Taiichi Ohno. “Ohno” style production lines were created in the engine plant in line with his concepts and thoughts on improvement. Unfortunately not many pictures exist from the time period. Here is one example though of a before and after image from a line conversion.
The image above depicts a crankshaft machining line in Ohno’s engine plant before kaizen on the left. Most notable is the build up of intermediate stock between processes due to batch style production. Also there is essentially one person per one machine in terms of operation.
To the right is the line after conversion. Machine to machine conveyors were added to enable a flow style of operation and synchronize the processes. Operators now tend to multiple processes. The intermediate work in process was also substantially reduced. The text box in Japanese does not reference any comparison metrics. No doubt however productivity, quality and lead-time all improved as well saving some space.