If the decided manufacturing process cannot balance the product
design requirements, as shown in Figure 3 a, there will be a situation with
more out-of-specification parts. If the effect of this poor quality is
managed within the production system, for example by putting extra
efforts in measuring, sorting procedures, re-work and scrapping, the
production cost is assumed to be high (Fischer, 2011). If the poor quality
is not given enough attention and the parts reach a down-stream
customer, like the assembly line, the costs tend to be very high and even
worse, if the final customer recognises parts out-of-specification, there is
a risk of extremely high expenses