1.4 What is manufacturing?
Manufacturing is a very broad activity, encompassing many functions – everything from purchasing to quality control! Later, we will concentrate on some of the manufacturing processes used to convert materials into products. But before doing this it is worth touching on some of the wider issues involved with running a successful manufacturing operation.
To consider manufacturing as a whole we clearly have to look beyond specific sets of materials and processes that lead to single products. Viewing manufacturing as a system provides a way of identifying which factors, whether internal or external, are important, and so aid decision making about choosing a particular manufacturing process in a particular situation.
This may sound needlessly complex, but is it? Sometimes the choice of which material and which process to use will not be trivial. Factors such as consumables for the manufacturing equipment, the amount of scrap produced, the speed of the process, the energy required, and so on, all may need to be considered in order to make a sensible decision about the best way of making the final product.
It is usual to consider both design and manufacture as part of the same manufacturing system. A typical systems diagram for such a holistic approach is shown in Figure 2.
In Figure 2, the arrows are showing flows – flows of resources, such as power, or the flow of ideas involved in the design process – the resource moves from one box to the next on the diagram. The arrows are not showing influences as in the multiple-cause diagram. Figure 2 is an example of a process flow diagram. It tries to describe the whole activity of manufacturing a product, from the initial idea through to delivery of the product to the customer; having designers as part of the manufacturing operation or manufacturing engineers being part of the design team is largely irrelevant. What is important is that design and manufacturing are not separate activities but must interact. A useful way to describe this interaction is shown in Figure 2 as the product design specification or PDS.