A significant influencing factor in the selection of materials and processes for manufacturing a product is the production volume.

One-off Production

For extremely limited or one-off production the materials are likely to be bought in small, relatively uneconomic, quantities and in forms that need further machining/processing. A jeweller might buy a strip of silver that needs to be drawn into thin sections or melted into the desired shape. A joiner might buy a length of timber which needs to be sawn and planed into the desired shape. A potter might buy a bag of clay which he/she shapes on a wheel. In each case the outlay on materials is small but uneconomic and in each case a significant amount of waste is likely to occur.
The tools that are used in one-off production are likely to be fairly basic ~ on a par with the tools that we have in our workshop. The advantage of this is that the product can be tailor-made to the customers specifications using relatively inexpensive hand and power tools. The disadvantage (as you will already be aware) is that it is very time consuming. Time is money and so the end product will carry a hefty price tag.

Batch Production

Once your manufacturing levels have reached tens or hundreds, there are significant savings to be made by employing efficient techniques for carrying out repetitive tasks. Your material costs are likely to be lower per item because you are ordering in bulk. It becomes worth your while constructing jigs so that, for example, a series of holes are drilled in the same place each time eliminating the need for time-consuming marking out. It is economical to construct a metal pattern for sand casting or a mould for vacuum forming. CNC machining can be used for repetitive machining tasks.
The time and money invested in setting up equipment to batch-produce an item is likely to be recouped by your profit margin on the finished product.

Mass Production

Mass production represents a big leap from one-off and batch production. There is a much greater initial commitment in terms of manufacturing equipment and facilities. Machines can cost millions and the tooling for these machines hundreds of thousands of pounds. The need to get the product right is imperative as it may require volumes of tens of thousands to recoup the investment.
The cost of materials per unit is at its lowest. Materials are ordered in bulk, often in the form of granules, powders or billets, to be processed within the factory. Waste is considerably reduced because the product is likely to be formed from the raw material as opposed to being shaped from a standard stock size using a wasting technique. Automation means that these machines require little human intervention, can run continuously, and produce the finished article much more rapidly, to a more consistent quality and cheaper than by using batch or one-off techniques.
The down-side is that it is difficult to make significant changes to the product and the level of initial investment makes it more of a gamble. It is estimated that one third of all new products are not readily accepted by the market.


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