Thesis Archive

A multi-objective material and process selection model for a single product considering quality and environmental impact (2008)

Roselle Jane S. Apuyan
Ralph Lester T. Que
Sean Philip N. Tangsoc

Abstract:

-Raw materials available in the market are gradually becoming scarce. This initialized the call for recycling and designing products that avoid resource consuming processes. Therefore, decisions on the selection of materials, as well as optimizing the quality state of products, are deemed to be important aspects to consider in making products since these determine the compatible manufacturing processes as well as the final product costs. In the same way, studies have shown that although product and process design were key product cost drivers, by taking supply chain concerns into account during the early stages of design, it becomes possible to operate a much more efficient supply chain. As such, the integration of design for manufacturing and design for the supply chain is important in order to fully optimize the system.

The purpose of this research is to design a multi-objective mathematical model that would minimize the total system costs as well as the environmental impacts that result from the materials and processes selected by the manufacturer in the production of a single product given that certain processes are infeasible to use to manufacture a product component and that certain materials can only be used for certain components. This study also includes the use of the Modified Reflected Normal (MRN) loss function to capture the quality loss of products. The model formulated was run using General Algebraic Mathematical Model System (GAMS) and was able to capture the system’s expected behavior. Using Design of Experiments (DOE), it was seen that using virgin raw materials would be more beneficial to the objectives of this study if there is a high degree of quality loss for reprocessing second-hand materials, approximately 80% higher than that from virgin raw materials, which leads to not only a higher total system cost, but also higher degree of environmental impact.

Adviser:

Mr. Richard Li
[email protected]