It is usual to classify types of production as job production, batch production and flow production. In job production, products are supplied to the special requirements of a customer, and the whole project is undertaken as one operation which is completed before passing, on to the next. A good example of this kind of work is shipbuilding. In job production a single item is produced at a time, whereas in batch production a number of similar items are produced in order to meet a continuing sales demand Batch sizes vary, but the quantity which is produced amounts to more than immediate requirements, and the surplus production is stored. Finally, in flow production, the manufacture of a product proceeds from one operation to another at a planned rate of output. It is argued that the type of production method which is employed depends on the development of an individual company. That. is to say, many factories begin manufacturing on a job production basis and proceed, as the volume of production increases, to batch and flow production methods. This is not always the case, however, since the type of production is not necessarily determined by the product volume which is aimed at. In fact, in the car industry, tools are produced by jobbing methods, components are produced by batch methods, and the final product is assembled by flow methods. Flow production is associated with flow layouts, whereas job and batch production are associated with process layouts. In a process layout, machines of a similar type are grouped together in the same section of the factory, and work in progress is moved from one part of the factory to another. In a flow layout scheme, the manufacturing equipment is arranged in the same sequence as the operations performed on the product. Each of these operations must be capable of processing work at the rate required for assembly of the final product, and the output for each operation must be balanced in order to provide a smooth flow of work. There are advantages in both types of layout. In a process layout system there is more flexibility, and a greater specialization of machines and labour is possible, while in a flow layout system it is not necessary to maintain a high level of stocks or to demand great skill in the workforce. Which of the following is NOT mentioned in the passage?