Generally, software re-engineering is economical and perfect way to provide much needed boost to a present software system. Software Re-engineering is like to obtain a fully completed software from existing software with additional features if needed. The overall process of Software re-engineering is to analyze the needed requiements & its contents. It also changes the needed contents or transforms the existing software system for reconstructing a novel software system. The difficult part in re-engineering is to understand the traditional system. Most of the software re-engineering mechanisms are aimed to achieve the common re-engineering objectives and the objectives are: improved software quality, reduced complexity, reduce maintenance cost and increased reliability. As a result, several traditional re-engineering mechanisms fail to verify the performance of individual functionality in existing software. This performance evaluation increases the complexity in re-engineering process. To minimizing the complexities in software re-engineering, this proposed system implements a novel approach named Enhanced Re-engineering mechanism. This enhanced mechanism introduces a new idea, before executing the re-build process the developer verifies the performance of particular function in existing system. After that, the function performance is compared with proposed algorithm. Based on the comparison process only rebuild process should be carried out. Finally this proposed mechanism reduces the complexities in software re-engineering.