A Decision System Using ANP and Fuzzy Inputs Jaroslav Ramík Silesian University Opava School of Business Administration Karviná Czech Republic e-mail: ramik@opf.slu.cz FUR XII, Rome, June 2006
Content Problem -AHP Dependent criteria – ANP Solution Case study Conclusion
Problem- AHP MADM problem – AHP AHP- supermatrix AHP- limiting matrix Content
MADM problem – AHP - Criteria - Variants Content
AHP – supermatrix Supermatrix: Content
AHP- limiting matrix Limiting matrix: - vector of evaluations of variants (weights) Content
Dependent criteria – ANP Dependent evaluation criteria – ANP Dependent criteria – supermatrix Dependent criteria – limiting matrix Uncertain evaluations Uncertain pair-wise comparisons Content
Dependent evaluation criteria – ANP Feedback Content
Dependent criteria – supermatrix - matrix of feedback between the criteria Content
Dependent criteria – limiting matrix - vector of evaluations of variants (weights) Content
Uncertain evaluations 1 0 aL aM aU Triangular fuzzy number Content
Uncertain pair-wise comparisons Reciprocity 0 ¼ 1/3 ½ 1 2 3 4 Content
Solution Fuzzy evaluations Fuzzy arithmetic Fuzzy weights and values Defuzzyfication Algorithm Content
Fuzzy evaluations Fuzzy values (of criteria/variants): Triangular fuzzy numbers: , k = 1,2,...,r Normalized fuzzy values: Content
Fuzzy arithmetic aL > 0, bL > 0 Addition: Subtraction: Multiplication: Division: Particularly: aL > 0, bL > 0 Content
Fuzzy weights and values Triangular fuzzy pair-wise comparison matrix (reciprocal): approximation of the matrix: Content
Fuzzy weights and values Solve the optimization problem: subject to Solution: i = 1,2,...,r Logarithmic method Content
Defuzzyfication Result of synthesis: Triangular fuzzy vector, i.e. Corresponding crisp (nonfuzzy) vector: where 1/3 zL zM xg zU Content
Algorithm Step 1: Calculate triangular fuzzy weights (of criteria, feedback and variants): Step 2: Calculate the aggregating triangular fuzzy evaluations of the variants: or Step 3: Find the „best“ variant using a ranking method (e.g. Center Gravity) Content
Case study Case study - outline Case study - criteria Case study - variants Case study - feedback Case study - W32* and W22* Case study - synthesis Case study - crisp case with fedback Case study - crisp case NO fedback Case study - comparison Content
Case study - outline Problem: Buy the best product (a car) 3 criteria 4 variants Data: triangular fuzzy pair-wise comparisons fuzzy weights Calculations: 1. with feedback 2. without feedback Crisp case: „middle values of triangles“ Case study
Case study - criteria Case study
Case study - variants Case study
Case study - feedback Case study
Case study - W32* and W22* Case study
Case study - synthesis Case study
Case study - crisp case with fedback Crisp case: aL = aM = aU Case study
Case study - crisp case NO fedback Crisp case: aL = aM = aU, W22 = 0 Case study
Case study - comparison
Conclusion Fuzzy evaluation of pair-wise comparisons may be more comfortable and appropriate for DM Occurance of dependences among criteria is realistic and frequent Dependences among criteria may influence the final rank of variants Presence of fuzziness in evaluations may change the final rank of variants Case study
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DĚKUJI VÁM (Thank You)