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Page 30 Table 3.9 Unit annual operation and maintenance costs Description Score No pumping is required 10 Part of the sewerage network requires pumping 5 All of the sewerage has to be pumped to the outfall or treatment plant 1 reflection of the importance of tourism to the national economy in which the example given was carried out. However, to say that it is three times more important is purely arbitrary. Criteria weights can only be decided upon after discussions with all groups concerned. As they are so arbitrary it is important that a sensitivity analysis is conducted on the results. This is discussed in more detail in the next section. 3.3.3 Scoring and Sensitivity Analysis The total score for a community is the sum of all the weighted scores (as shown in Table 3.1). Communities can be ranked with the highest score being first and the lowest score being last. The high-ranking communities are those most favoured for sewerage. The results of ranking can never be completely objective because Table 3.10 Community ranking Rank Town in Table 3.1 Weighted score 1st re-ranking Weighted score 2nd re-ranking Weighted score Priority 1 B 90 B 93 B 54 2 J 79 J 84 L 44 High 3 L 77 L 80 C 43 4 D 66 C 66 J 41 5 C 65 F 60 F 38 Medium 6 F 58 D 58 D 32 7 G 39 A 41 A 26 8 A 38 E&G 37 E&G 23 9 H 37 Low 10 E 36 H 34 H 22 11 K 24 K 29 K 17
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