Seite - 1274 - in Book of Full Papers - Symposium Hydro Engineering

5.3. DEFINE THE REHABILITATION ACTIONS NEEDED After evaluation of current condition of each structure, the required remedy actions were defined. The action in this study varies from maintenance corrective action to rehabilitation or replacement of the structure. Cost of each action was estimated. Expected benefit from that action was assumed as the due enhancement in the scoring system related to the deterioration dealt with by the action. 5.4. MULTI CRITERIA DECISION ANALYSIS (MCDA) MCDA establishes preferences between options by reference to an explicit set of objectives that the decision-making body has identified, and for which it has established measurable criteria to assess the extent to which the objectives have been achieved. The scoring and weighting technique was used for the MCDA in this study. Both scoring and weighting rules were set by a series of discussions and meetings by specialised experts in the hydraulic structure work field. Combining the scores and weights of each criterion, shown in figure 6, gave an overall value that reflected the priority of actions. 𝑆 𝑡 𝑟 𝑢 𝑐 𝑡 𝑢 𝑟 𝑒 𝑆 𝑐 𝑜 𝑟 𝑖 𝑛 𝑔 = ∑( 𝑃 𝑟 𝑖 𝑜 𝑟 𝑖 𝑡 𝑦 𝑓 𝑎 𝑐 𝑡 𝑜 𝑟 𝑠 𝑐 𝑜 𝑟 𝑒 )𝑛 𝑥 (𝑃 𝑟 𝑖 𝑜 𝑟 𝑖 𝑡 𝑦 𝑓 𝑎 𝑐 𝑡 𝑜 𝑟 𝑤 𝑒 𝑖 𝑔 ℎ𝑡 )𝑛 𝑛 𝑖 =1 Where n is the total number of factors = 20. Combining these priority results with the financial criteria led to 6 different scenario plans. The model can handle any number of criteria and lead to many scenarios. But finally, when one set of criteria is selected, only one scenario plan is valid, and that is the best decision. Table 2 Combination of criteria and corresponding scenario plans Combinaison de critères et de plans de scénario correspondants Plan 1 Plan 2 Plan 3 Plan 4 Plan 5 Plan 6 Absolute cost of actions ● ● ● different 5-year-plan budgets ● ● ● ● Top benefit/cost-ratio actions ● ● ● Group similar actions in different structures ● ● ● 1274