Such variability can be observed in measurable characteristics of products ad processes, and may be seen to exist at various stages over the life cycle of products from market research to customer service and final disposal.

• 这种变异可通过产品和过程可测量的特性观察到，并且在产品的整个寿命周期（从市场调研到顾客服务和最终处置）的各个阶段，均可看到其存在。