Weighted Sum Method: An Introduction

A short tutorial on Weighted Sum Method for decision making. This tutorial is a part of "Introduction to MCDM".The tutorial introduces the procedure to identify better option among many alternatives.

1. Weighted Sum Method Dr. Mrinmoy Majumder Course Name : Intro to Multi Criteria Decision Making Methods Lecture No .09 out of 15 https://opticlasses.teachable.com Follow me on : RG : Mrinmoy Majumder Twitter : kuttu80 Founding Honorary Editor http://www.baipatra.ws http://www.energyinstyle.website

2. What is Weighted Sum Method In decision making problems, the Weighted Sum Model or Method(WSM) ( Fishburn et.al.,1967) is the simplest known multi-criteria decision making(MCDM) method for evaluating a number of alternatives in terms of a number of decision criteria. Applicable only when all the data are in exactly the same unit.  Let  w j  describe the relative weight of significance of the criterion  C j  and  a ij  is the performance value or normalized magnitude of alternative  A i  when it is evaluated in terms of criterion  C j . Then, the total (i.e., when all the criteria are considered simultaneously) importance of alternative  A i , denoted as  A i WSM -score Reference : Fishburn , P.C. (1967). "Additive Utilities with Incomplete Product Set: Applications to Priorities and Assignments".  Operations Research Society of America (ORSA), Baltimore, MD, U.S.A .

3. How it Works ?

4. Example of ANP

5. Example Contd. If importance of Cost is more compared to the importance of Speed with respect to the goal of the decision making, i.e., buying a car. The value of alternatives with respect to cost and speed was normalized(value/sum of all values).Here Cost is a non-preferred criteria as more the cost of the alternative less will it be preferred choice of selection Goal : Buy a car Cost (Relative Weight : 0.667) Speed (Relative Weight : 0.333) Sum of the product function of Relative Weight of Criteria and the value of the alternative for that criteria A ( WSMScore ) Rank based on importance M 0.500 0.200 0.5x0.667+0.2x0.333 0.400 1 J 0.300 0.500 0.3x0.667+0.5x0.333 0.367 2 T 0.200 0.300 0.2x0.667+0.3x0.333 0.233 3