New Product Demand and Design Requirements

Why it matters

When a new product is launched, the first layout drawing is often prepared before the demand table. The result is that demand is sought to fit the chosen machine, and the real requirements of the product are added later. A good start is to state which product will be delivered in which period under which acceptance criterion. The demand quantity alone is not enough; the product mix, delivery frequency, likelihood of change and the source of the forecast are design inputs as well. The firm order, the sales forecast and possible growth are kept apart. All of them can be examined, but they do not have the same level of confidence. Writing a forecast in capital letters does not make it a binding order.

Takt time divides the net available time of a defined period by the quantity of good units wanted in that period. This number is not proof that every task can really be done in that time; it shows the delivery rhythm the design must respond to. If the low, base and high demand scenarios are built with the same time limit, the range over which the resource requirement changes becomes visible. When planned breaks are subtracted from the shift length, the same break is not counted a second time as a capacity loss. Effects such as maintenance, product changeover and nonconformities are assessed separately, with explicit assumptions. Silently changing the denominator during a design comparison can make the options look stronger than they are.

The bill of materials shows which components, and how many of each, a finished product needs. Shared parts accumulate the load coming from different products on the same resource. Meeting the finished-product demand does not mean the shared component is automatically sufficient. Even if one product sells less, it can place much more load on the shared operation. For this reason the final assembly rhythm and the component requirement are calculated separately. The design requirements then describe under which quality, safety and function conditions this load is met. A request with no acceptance criterion cannot be counted as a requirement closed in the investment decision. Missing data stays visible and an owner is assigned.

The output of this lesson is not one perfect forecast. The output is a requirements table that shows which calculation and which decision will be reopened when demand changes. Product, process and investment decisions are discussed on the basis of this table. The cost of a design that raises capacity but makes control harder becomes visible here. In the next lesson, process options will be compared against the same requirements. For this reason, instead of fixing every detail early, the conditions that are expensive to change should be verified early. The worker's safe access, correct orientation of the part and the ability to take the acceptance measurement are not left as details to be solved only after production starts.

Formula