1. Introduction to Multi Criteria Analysis MCA

2. Multi Criteria Analysis
MCA: aims to rank alternative strategies when the effect of these strategies cannot be translated into one single measuring scale
Score card: represent the impacts of alternative strategies on criteria
Wt.
Alt.1
Alt.2
Alt.3
Criterion 1 1
good
v. good
bad
Criterion 2 2
+++ --
Criterion 3
1.5
5.5 9
Criterion 4
- 0.2
- 0.3
+ 0.5
Criterion 5 3
20,000
50,000
30,000
Total score
???

3. Multi Criteria Analysis
Steps:
Generation of alternatives
Formulation of criteria
Filling score card
Standardization of scores
Application of weights
Ranking of Alternatives
Sensitivity analysis
cautions
Avoid double counting (e.g. groundwater level and cost of pumping)
Specification of units (negative or positive, best or worst)
Score cards represent one scenario
Score card are made for one time horizon
Be aware of uncertainties

4. Multi Criteria Analysis
Approaches:
Weighted sum method
Pairwise comparison (concordance index)
Standardization Methods
Subjective/qualitative scores can be translated into 1-10 scale
For Quantitative scores the following formula can be applied:

5. Multi Criteria Analysis
Weighted Sum:
Wt.
Alt.A
Alt.B
Criterion 1 1
0.9 *1
0.2*1
Criterion 2 2
0.4*2
0.7*2
Criterion 3
0.6*2
Wtd Sum
2.5
2.8

6. MCA Example
The following table include some data about the different technologies
for brackish water purification.
We wish to select which technology is best for Gaza ??
Criteria
Wt.
Brackish EDR
Brackish RO
Barckish IX
capital cost
130000
100,000
110000
O&M cost ($/m3)
0.3
0.25
0.35
recovery rate (%)
95%
70%
97%
suitability to gaza water
moderate
high
low
quality of water (TDS)
100
150
250
environmental impacts -1 -3 -2
availability of membranes and chemicals