Multi-Criteria Analysis

Question 1

What is the value of a multi criteria analysis?

Answer 1

• It helps to evaluate alternatives: solutions, scenarios, land use options, products etc.
• MCA works with criteria with different dimensions, so you do not have to convert indicators ( e.g. into monetary values), and you can consider criteria that are difficult to measure ( e.g. social or religious aspects)
• MCA is a tool that can help evaluate the relative importance of all criteria involved and reflect their importance in the final decision making process.
• Helps to reach consensus in a multi-disciplinary team or group of stakeholders
  
  • Team members don’t have to agree on the relative importance of the criteria or the rankings of the alternatives, each member enters his/her own judgements and makes a distinct, identifiable contribution to a jointly reached conclusion.
• Helps to make the decision making process transparent

Question 2

What is MCA?

Answer 2

Multi-Criteria Analysis is a decision making tool, developed for a complex multi-criteria problems that include quantitative and/or qualitative aspects of the problem in the decision making process.

Question 3

What is the purpose of MCA in ESA?

Answer 3

• ESA involves the study of complex environmental problems by identifying and analysing causes, mechanisms, processes, impacts, and potential solutions.
• MCA is used to compare and rank alternatives taking into account and evaluating their respective consequences.

Question 4

What are the characteristics of MCA?

Answer 4

• Criteria have different dimensions, e.g. costs, deposition levels, area of damaged ecosystems
• Criteria may differ in weight, e.g. acidification may be considered a bigger problem than eutrophication
• Weights depend on ‘vision’, e.g. various people have various preferences
• Qualitative and quantitative information, e.g. opinions about environment versus quantitative emissions loads

Question 5

Describe a generic procedure for MCA?

Answer 5

1. Establish the decision context:
   
   • Identify the overall goal of decision making
   • Identify (sub)objectives
     
     • What would distinguish between a good solution and a bad one?
   • Convert objectives to measurable (sub)criteria
     
     • Once you have set a criteria try to group them ( e.g. costs, effect on the environment, socio-economic consequences, side-effects on the issues)
     • Assess the criteria on:
       
       • completeness
       • redundancy
       • operationally
       • mutual independence of preference
       • double counting
       • size
       • impacts over time
2. Identify alternative options
3. ‘Score’ options performance against criteria
   
   • Assess the expected performance ( consequences) of each solution against each criterion. Result is -performance matrix. This can be done:
     
     • Quantitatively, e.g. in monetary terms, number of accidents, increase of CO2 emission, etc.
     • Qualitatively, e.g. in words ‘no significant impact’
   • To keep in mind:
     
     • Take care that the scores are comparable
     • Use the same sense of direction: usually better performance means a higher score
     • Use e.g. interval scales (0-100) or based on Likert scale 1-5
4. ‘Weight’ criteria
   
   • Assign a weight ( value) to each of the criteria to reflect their relative importance
   • reflects the subjective opinion of a group of experts, stakeholders or actors
5. Combine the weights and scores for each option to derive an overall value
   
   • Si = w1si1 + w2si2 + ….+ wnsin = sum(n; j =1) wjsij
6. Examine the results: evaluate & rank options
7. Sensitivity analysis

Question 6

What are the different methods to assign weights?

Answer 6

• Ranking: assigning each criterion a rank that reflects its perceived degree of importance relative to the decision being made. This criteria can then be ranked ( first, second, etc.)
• Rating: similar to ranking, but criteria are assigned “percentage scores” between 0 and 100, while the total scores for all criteria must add up to 100

Question 7

What are the two types of ranking?

Answer 7

• Ordinal ranking: each expert is asked to put the list of criteria in order of importance
• Regular ranking: assigns each criterion a rank depending on its perceived importance

Question 8

What are the advantages of rating?

Answer 8

It provides both ordinal ( order of importance) and cardinal ( difference in magnitude between two criteria) measure of importance