In this paper the concept of Fuzzy as traditional tools for modeling will be discussed. Traditional tools for formal modeling reasoning, and computing are crisp, deterministic , and precise in character , but in many real world decision – making situations it is not possible to fulfill perfectly all conditions and objective of a constraint satisfaction problem (CST) which models the environment that has to optimized this applies to Civil Engineering tasks as well as to most other technical environments. Different reasons lead us to introduce a new concept for modeling constraint satisfaction problems in order to get a more suitable representation of real-world decision-marking problem.

Fuzzy , CST , SCI , TW , OWA , civil Engineering , Possibility Theory