MCDA is based on deriving an overall score for the alternative being analysed. A primary advantage of MCDA is the provision of a highly structured decision-making technique. Goals, inputs, alternatives, criteria and weights serve as the core components of MCDA. Within a decision-making problem, criteria are used to evaluate the performance of all the alternatives. Relative importance factors (weights) of the relevant criteria are defined by the decision maker and these factors are numerical representations of the preference of the decision maker based on background information and experience. MCDA provides a numerical score, or rating, assigned to a given alternative with respect to each criterion. Typically, one alternative does not satisfy all the important criteria; alternatives that are more beneficial for instance are usually more costly, hence some compromise or trade-off is usually evident among the goals.