Abstract: Software reusability is an essential characteristic of
Component-Based Software (CBS). The component reusability is an
important assess for the effective reuse of components in CBS. The
attributes of reusability proposed by various researchers are studied
and four of them are identified as potential factors affecting
reusability. This paper proposes metric for reusability estimation of
black-box software component along with metrics for Interface
Complexity, Understandability, Customizability and Reliability. An
experiment is performed for estimation of reusability through a case
study on a sample web application using a real world component.