The objective of this book is to support software decision makers in handling additional software complexity introduced by product line architectures. This book is about to discuss the scientific research and development work done in managing variable behavior of traditional and Product Line Architecture based software applications by analyzing their preprocessed source code with the use of Metrics. In order to meet the objectives an approach to analyze, visualize, and measure the Product Line specific characteristics of the C/C++ source code has been proposed i.e., Zeeshan Ahmed C-Preprocessed Source Code Analyzer (ZAC). This approach is validated by implementing into a software measurement tool and experimenting using some real time software applications.