Abstract: Maintainability is an essential software quality factor that is useless if it is not available at an initial stage in the software development life cycle. It becomes more important in the case of object oriented design. Estimating maintainability of object oriented design near the beginning in the development cycle, mainly at design phase; significantly reduce the development cost and rework, and as well as assists the software designers and developers for delivering high quality maintainable software within time and budget. This paper illustrates the need and significance of maintainability at design phase and build up a multivariate linear Maintainability Estimation Model for Object-Oriented Design. Developed model estimates the maintainability of class diagrams in respect of their Extendibility, Reusability. Lastly the developed models have been validated using experimental tryout.

Keywords: Maintainability, Estimation, Software Metrics, Object Oriented Design.