Reverse Engineering is the process which recovers the design artifacts of a software system by using its Size of source code, Available source code type, Abstraction level, Documentation type support. This research focus on the different case studies of recovery of Metrics and is elaborated by using the method of Reverse Engineering, to measure the complexity of the recovery of artifacts for the maintenance task. During this process of analyzing a subject system and in this way representation of a system is created at a higher level of abstraction. It represents an overview of the yield of reverse engineering and reviews cardinal achievement and areas of application, shedding light on key open research issues of the future.