Components vs. Objects Components vs. Objects

Component-based software engineering means constructing new systems from already existing, service-providing components. Object-based software engineering means constructing a new system in terms of interacting, distinct units of information and services called objects. Both components and objects have encapsulation properties and are accessed via well-de ned interfaces. Both components and objects are considered to improve the reuse of software and to alleviate its evolution phase. Finally, both notions are thought of being natural abstractions of real-world entities. Moreover, a real-world entity can be modelled or implemented using either notion. Their similar appearance in abstract modelling gives rise to confusion in distinguishing between these two notions. In this paper we examine the conceptual di erence between components and objects, and aim at clarifying it. Based on this, we also propose a guideline for a software engineering process that incorporates both notions and exploits components and objects at their real potential.