Date Added: Sep 2010
In order to guarantee the use of good analysis and design practices and an easier maintenance of software, analysts and designers may use patterns. A pattern is a consensus on the most efficient solution to solve a given problem. The use of a pattern is the guarantee to re-use the most adequate solution and thus, to maintain a consensual quality with analysis and design. To assist designers, the design patterns catalog of Gang of Four provides a set of solutions. If a designer uses the GoF on his design, the people consider that their ensured to select the best known solution to solve his problems.