E MBEDDED S YSTEMS S OFTWARE T RAINING C ENTER S OFTWARE D ESIGN C OPYRIGHT © 2011 DSR C ORPORATION

Objectives  Understand what software design is  Understand the software design techniques and approaches C OPYRIGHT © 2011 DSR C ORPORATION 2

Agenda 1. What is Software Design? 2. Software Design Strategies 3. Software Design Techniques 4. Key Issues in Software Design 5. Software Architectural Styles and Patterns 6. Software Design Documentation 7. Software Design Quality C OPYRIGHT © 2011 DSR C ORPORATION 3

Coupling and Cohesion: Coupling C OPYRIGHT © 2011 DSR C ORPORATION Pfleeger and Atlee, Software Engineering: Theory and Practice, Chapter 5 4

Coupling and Cohesion: Coupling (cont.)  We can measure coupling along a range of dependence C OPYRIGHT © 2011 DSR C ORPORATION Pfleeger and Atlee, Software Engineering: Theory and Practice, Chapter 5 5

Coupling and Cohesion: Cohesion C OPYRIGHT © 2011 DSR C ORPORATION Pfleeger and Atlee, Software Engineering: Theory and Practice, Chapter 5 6

Coupling and Cohesion: Cohesion Examples C OPYRIGHT © 2011 DSR C ORPORATION Pfleeger and Atlee, Software Engineering: Theory and Practice, Chapter 5 7

Summary  Software Design is a crucial process of the software life cycle  It involves design strategies, techniques, styles, and patterns  Different aspects must be taken into consideration  Software Design Document must contain as much as possible the information necessary for implementation as well as the design flow  Design validation is one way to achieve good product quality C OPYRIGHT © 2011 DSR C ORPORATION 8

References 1.SWEBOK. Guide to the Software Engineering. Body of Knowledge Version / A project of the IEEE Computer Society Professional Practices Committee 2.Software Engineering: Theory and Practice / Shari Lawrence Pfleeger 3.IEEE Std , IEEE Standard Glossary of Software Engineering Terminology C OPYRIGHT © 2011 DSR C ORPORATION 9

Questions and exercises 1.What are the main and supplementary software design activities? What are the input and output for every activity? 2.What are the key software design strategies? Give the characteristic for every strategy. When it is used? What kind of the diagrams is used for its description? 3.What are the key software design techniques? Give the short characteristic for every technique. 4.What are coupling and cohesion? What software quality characteristic it influences the most? What the coupling among components depends on? Give the example of low cohesion and high cohesion. C OPYRIGHT © 2011 DSR C ORPORATION 10