A product design with fuzzy axiomatic design and goal programming: An application in a soft drink plant

Keywords: Product design problem, goal programming, fuzzy axiomatic design technique In this thesis, a product design problem of a company operating in the beverage sector was handled and solved. The firm was faced with a beverage bottle design problem, which is unclear whether it would continue mass production after the first batch of production. If the company has to make mold and recipe investments on the production line for the product concerned, the project will not be profitable as the fixed costs for the unit product will increase. Therefore, the company wants to respond to the customer's demand without changing the existing production line specifications. In order to do this, it decided to design the bottle of the product to be produced based on an existing bottle design. The new bottle design problem has three goals: not changing the current line specifications, keeping the production speed at a certain level, and also considering customer liking. Customer liking was expressed by fuzzy data to better express the natural decision-making processes of human. In this study, fuzzy data belonging to customer liking was defuzzificated by the Fuzzy Axiomatic Design (FAD) technique and the obtained values were used in a mixed integer non-linear Goal Programming model which also took into consideration these three objectives. Before doing this study, new bottle design projects had been carried out by trial and error method. Roughly determined bottle parameters had been given to the supplier. If the drawing was approved, the trial mold had been purchased. The preforms had been blowing by the test mold and they had been tested in the line filling with water. As a result of this test, the supplier's design had been approved or corrections had been requested. These stages continued until the approval had been received. Under favour of proposed solution approach in this thesis, the problem has been dealt with analytically, and since the trial and error method was abandoned, time, labor, energy, mold and preform costs were saved. Although it is possible to find the studies which uses the Axiomatic Design and Goal Programming approaches separately in the literature, there is no study which uses FAD and non-linear Goal Programming approaches together in the literature. In this respect, this thesis presents a different perspective with the proposed solution approach of the product design problem and contributes to the literature.