The Simple additive weighted model result in the formation of a function allowing the ranking from best to worst of all project options. the information obtained is thus quite comprehensive,with a cardinal score derived of each element in question.however, this rich of information is a direct consequence of the high quality of data required to be input into it, data that may not be readily to hand if the engineering evaluation of the various options is preliminary in nature.Furthermore, the decision maker may not actually require the high level of information provided by the additive model.What may be required is a decision methods that generates a simple ranking of the options involved rather than an actual score for each. In such a situations, Concordance Analysis may be the most appropriate decision model. Furthermore,it is a suitable methodology in situations where it may not be necessary to know the relative positions in the final hierarchy of all options. For example, if it is known that option a is better than options b and c, it may be irrelevant to the decision maker what the relative position of b and c is. It should be possible for two to remain incomparable without endangering the decision process. In some engineering situations is might actually be quite useful to highlight the incomparability of a number of options because of the absence of sufficient information to allow any meaningful comparison. In such circumstances, the result will reflect a more realistic solution given the quality of data available. if the information is not of a sufficiently high quality to produce a ranking directly connecting all options. then what is termed a partial ranking will be derived where some options are not directly compared. In practice, concordance techniques are generally used to produce a shortlist of preferred options from a relatively large number of project options rather than one single best projection.