tailieunhanh - Lecture Software engineering - Chapter 7: Requirements modeling: Flow, behavior, patterns, and webapps

For some types of software, the use case may be the only requirements modeling representation that is required. For others, an object-oriented approach is chosen and class-based models may be developed. Chapter 7 provides knowledge of requirements modeling: Flow, behavior, patterns, and webapps. | Chapter 7 Requirements Modeling: Flow, Behavior, Patterns, and WebApps 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. Requirements Modeling Strategies One view of requirements modeling, called structured analysis, considers data and the processes that transform the data as separate entities. Data objects are modeled in a way that defines their attributes and relationships. Processes that manipulate data objects are modeled in a manner that shows how they transform data as data objects flow through the | Chapter 7 Requirements Modeling: Flow, Behavior, Patterns, and WebApps 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. Requirements Modeling Strategies One view of requirements modeling, called structured analysis, considers data and the processes that transform the data as separate entities. Data objects are modeled in a way that defines their attributes and relationships. Processes that manipulate data objects are modeled in a manner that shows how they transform data as data objects flow through the system. A second approach to analysis modeled, called object-oriented analysis, focuses on the definition of classes and the manner in which they collaborate with one another to effect customer requirements. Flow-Oriented Modeling Represents how data objects are transformed at they move through the system data flow diagram (DFD) is the diagrammatic form that is used Considered by many to be an “old school” approach, but continues to provide a view of the system that is unique—it should be used to supplement other analysis model elements The Flow Model Every computer-based system is an information transform computer based system input output Flow Modeling Notation external entity process data flow data store External Entity A producer or consumer of data Examples: a person, a device, a sensor Another example: computer-based system Data must always originate somewhere and must always be sent to something Process A data transformer (changes input to output) .