Component-level design occurs after the first iteration of architectural design has been completed. At this stage, the overall data and program structure of the software has been established. The intent is to translate the design model into operational software. Chapter 10 provides knowledge of component-level design. | Chapter 10 Component-Level Design Slide Set to accompany Software Engineering: A Practitioner’s Approach, 7/e by Roger S. Pressman Slides copyright © 1996, 2001, 2005, 2009 by Roger S. Pressman For non-profit educational use only May be reproduced ONLY for student use at the university level when used in conjunction with Software Engineering: A Practitioner's Approach, 7/e. Any other reproduction or use is prohibited without the express written permission of the author. All copyright information MUST appear if these slides are posted on a website for student use. What is a Component? OMG Unified Modeling Language Specification [OMG01] defines a component as “ a modular, deployable, and replaceable part of a system that encapsulates implementation and exposes a set of interfaces.”” OO view: a component contains a set of collaborating classes Conventional view: a component contains processing logic, the internal data structures that are required to implement the processing logic, . | Chapter 10 Component-Level Design Slide Set to accompany Software Engineering: A Practitioner’s Approach, 7/e by Roger S. Pressman Slides copyright © 1996, 2001, 2005, 2009 by Roger S. Pressman For non-profit educational use only May be reproduced ONLY for student use at the university level when used in conjunction with Software Engineering: A Practitioner's Approach, 7/e. Any other reproduction or use is prohibited without the express written permission of the author. All copyright information MUST appear if these slides are posted on a website for student use. What is a Component? OMG Unified Modeling Language Specification [OMG01] defines a component as “ a modular, deployable, and replaceable part of a system that encapsulates implementation and exposes a set of interfaces.”” OO view: a component contains a set of collaborating classes Conventional view: a component contains processing logic, the internal data structures that are required to implement the processing logic, and an interface that enables the component to be invoked and data to be passed to it. OO Component Conventional Component Basic Design Principles The Open-Closed Principle (OCP). “A module [component] should be open for extension but closed for modification. The Liskov Substitution Principle (LSP). “Subclasses should be substitutable for their base classes. Dependency Inversion Principle (DIP). “Depend on abstractions. Do not depend on concretions.” The Interface Segregation Principle (ISP). “Many client-specific interfaces are better than one general purpose interface. The Release Reuse Equivalency Principle (REP). “The granule of reuse is the granule of release.” The Common Closure Principle (CCP). “Classes that change together belong together.” The Common Reuse Principle (CRP). “Classes that aren’t reused together should not be grouped together.” Source: Martin, R., “Design Principles and Design Patterns,” downloaded from http:, 2000. Design .
