In computer software development, genetic Improvement is the use of optimisation and machine learning techniques,particularly search based software engineering techniques such as genetic programmingto improve existing software.The improved program need not behave identically to the original.For example, automatic bug fixing improves program code by reducing or eliminatingbuggy behaviour.In other cases the improved software should behave identically to the old versionbut is better because,for example:it runs faster,it uses less memory,it uses less energyorit runs on a different type of computer.GI differs from,for example,formal program translation,in that it primarily verifies the behaviour ofthe new mutant version by running both the new and the old software on test inputsand comparing th