Jo May 24, 2022

Materials selection is a multi-criteria decision-making (MCDM) whereby materials designers and engineers have to select optimal material among two or more alternatives based on two or more criteria.

Many MCDM methods are applicable to the materials selection. These include rank sum ratio (RSR), simple additive weighting (SAW), weighted product method (WPM), analytic hierarchy process (AHP), technique for order preference by similarity to ideal solution (TOPSIS), VIse Kriterijumska Optimizacija Kompromisno Resenje (VIKOR) method, elimination and et choice translating reality (ELECTRE) method, preference selection index (PSI) method, preference ranking organization method for enrichment evaluations (PROMETHEE), grey relational analysis (GRA), complex proportional assessment (COPRAS) method, range of value method (ROVM), EXPROM, etc.

As materials selection may vary with the weights of materials selection criteria, the weights of materials selection criteria play an important role in materials selection by the MCDM methods.

Up to now, analytic hierarchy process (AHP) and entropy weighting method have widely been used to determine the weights of materials selection criteria. The AHP method is a subjective method while the entropy weighting method is an objective method. While objective weighting methods such as the entropy method fail to reflect the opinions of the materials designers and engineers, the AHP method can do it.

This is why the AHP method has mostly been applied to determine the weights of the materials selection criteria in many materials selection problems.

However, it still has some drawbacks. The major drawbacks to the AHP are as follows:

First, it is difficult to meet the consistency requirement of the pairwise comparisons.

Second, the pairwise comparison matrix (PCM) can hardly be constructed.

The solution is the introduction of a PCM construction method based on a new simplest questionnaire and a new modifying method of inconsistent PCM based on CR decrements.

Three indices are introduced to evaluate the effectiveness of the modifying method of inconsistent PCM.

• CR decrement ΔCR(A,B):

• Deviation index DI(A,B):

• Consistency ratio improving rate CRIR(A,B):

The results of analysis show that the simplest questionnaire helps materials designers and engineers to perform pairwise comparison judgments and the construction of PCM simply, easily and concisely without confusion, even if they have no knowledge and experience about the AHP method and that the modifying method based on CR decrements improves the consistency of inconsistent PCM better and faster by modifying a smaller number of elements with a smaller amount of modification.

This indicates that the simplest questionnaire and the modifying method could be widely used for calculating the weights of materials selection criteria or materials property indices in materials design and applications such as materials selection and optimization.

You can find more information about this in the paper “Materials selection criteria weighting method using analytic hierarchy process (AHP) with simplest questionnaire and modifying method of inconsistent pairwise comparison matrix” presented by Yang Won Chol, a researcher at the Faculty of Materials Science and Technology, to the SCI Journal “Proc IMechE Part L: Journal of Materials: Design and Applications” 2022, Vol. 236(1) 69–85.