Weighting of dependent and target-based criteria for optimal decision-making in materials selection process: Biomedical applications

The selection of the most appropriate material, or combination of materials, is a demanding intellectual process that takes a lot of time and experience. There are a large number of established and newly developed materials, and their associated materials processes, necessitating the simultaneous consideration of many conflicting criteria. This has highlighted the importance of the developing field of multi-criteria decision-making (MCDM) to the material selection process which is especially useful for high technology market where product differentiation and competitive advantage are often achievable with just small gains in material performance. It is clear that decision-making techniques that address target criteria as well as cost and benefit criteria can help engineering designers make better informed choices of materials. Despite the progress has been made in the ranking of materials for target-based criteria, there is no formalized technique for calculating the weighting dependency when target criteria must be taken into account in material selection problems that usually deals with databases. Therefore, to overcome this shortcoming, the strategy of using dependent weightings is extended in this research. Also, an alternative method is proposed to incorporate the correlation, objective, and subjective weightings effectively when there is uncertainty in the importance of three types of weights. This issue is very important for inexperienced designers. The updated procedure is validated through biomedical applications. The first example demonstrates the importance of dependency weighting in amalgam tooth filling material selection and the second one is a hip joint prosthesis material selection problem, which includes target criteria. Furthermore, a model of continuous improvement in product development is outlined, and it is highlighted that the material selection/development is a permanent and endless task for sustainable and profitable growth.