the statue of electronic publish :
United States -- Pennsylvania:Ph.D;(The Pennsylvania State University);2012
abstract :
However, since warranty costs are only part of the external failure costs, the first set of proposed integrated models run the risk of underestimating the external failure costs and jeopardizing the accuracy of the models results. This issue is addressed by proposing a second set of integrated parameter and tolerance designs models, which incorporate in them microeconomic and marketing concepts, such as pricing and demand functions. In these integrated models, instead of listing and estimating all external failure costs other than the warranty costs, these external failure costs are modeled as part of the customer's decision of the amount he or she is willing to pay for the product. That is, the customer sets the purchase price based on a tradeoff between the amount of gained satisfaction and the perceived risk of using the product. As a result, the objective of these integrated models is to maximize the profit, which is the difference between the selling price and the total cost of the product, as opposed to minimizing total cost. After surveying pricing and demand models from the microeconomic and marketing literature, it is found that most pricing models use product manufacturing and quality costs in a very crude manner. Therefore, not only do the proposed integrated parameter and tolerance designs models provide a better representation of the external failure costs, but they also provide a better representation of manufacturing and quality costs of the product in the microeconomic and marketing decisions models. That is, the proposed integrated models bridge the gap between marketing and manufacturing operations and decisions by eliminating unnecessary assumptions and poor links from both areas. Several numerical examples are presented to validate the proposed models and show their flexibility and applicability to a wide range of problems. For the first set of integrated models, in which microeconomic and marketing decisions are not considered, the examples include the cases of linear and nonlinear relationships between the product's main quality characteristic and the quality characteristics of its components as well as the case of finite manufacturing processes. For the second set of integrated models, in which microeconomic and marketing decisions are considered, the numerical examples include the cases of static market analysis approach for a general demand function, a monopoly, and a duopoly competition as well as the case of a dynamic market analysis approach. In the different numerical examples, a variety of optimization and analysis techniques, such as nonlinear programming, integer programming, response surface methodology, simulation, and sensitivity analysis, are employed to show the methodology of handling the different design problems.