Optimization of parameters means finding their right values that give the best product. When the application changes, the definition of a best product changes, which changes the right values. For example, if a polymer bearing is made, it must have a high surface finish. In this case, a product is best when it has a high surface finish. If a polymer door handle is made, the requirement is not to have a high but a low surface finish so it can provide adequate grip in use. In this case, the product is best when it has a low surface finish. Thus, the definition of a best product is not the same as that in the previous case, giving two sets of optimized parameters for two definitions.