1. CHAPTER.2: Requirements Engineering Processes
By:
Dr. Wa’el Jumah AL-Zyadat
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2. Requirements Engineering Processes
OUTLINES:
RE BASIC PROCESS.
RE EVOLUTIONARY PROCESS.
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3. Requirements Engineering Processes
1.0 - RE BASIC PROCESS.
1.1- RE Process: A Basic Framework RE Process: Spiral Model RE Processes: RAD (Role Actor Diagram) IEEE Standard for SRS 1.6- RE in Agile Methods
Requirements Engineering Processes 
2.0 - RE EVOLUTIONARY PROCESS
2.1- RE Evolutionary Process RE in Software Lifecycle
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4. Many variations and extensions 3 fundamental activities:
1.0 - RE BASIC PROCESS.
1.1- RE Process: A Basic Framework.
Many variations and extensions 3 fundamental activities:
Understand (formally) describe, Attain an agreement on, the Problem
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5. 1.1- RE Process: A Basic Framework.
1.0 - RE BASIC PROCESS.
1.1- RE Process: A Basic Framework.
Elicitation: determine what’s really needed, why needed, whom to talk to
Specification: produce a (formal) SRS model: translate "vague" into "concrete", etc. make various decisions on what & how
Validation: assure that the SRS model satisfies the users’ needs
As one of the processes in software engineering, Requirements Engineering (RE) plays a vital role in ensuring the overall success of the software engineering process. However, many of the substantial problems that the software industry faces today are still the same as the ones discovered during the software engineering crisis 36 years ago [Jiang, L. [2005]
SRS: Software Requirements Specification 
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6. 1.2- RE Process: Spiral Model.
1.0 - RE BASIC PROCESS.
1.2- RE Process: Spiral Model.
3- Testable
1- Complete
2- Traceable:
4-Consistent
8- Using “Shall” and Related Words
4-Consistent
5- Feasible
6-Uniquely Identified
7- Design Free
critical attributes:
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7. 1.2- RE Process: Spiral Model.
1.0 - RE BASIC PROCESS.
1.2- RE Process: Spiral Model.
Requirements elicitation: Requirements discovered through consultation with stakeholders
Requirements analysis and negotiation: Requirements are analyzed and conflicts resolved through negotiation
Requirements documentation: A requirements document is produced Feasible
Requirements validation: The requirements document is checked for consistency and completeness
what the advantages of using Spiral Model ?
what the disadvantages of using Spiral Model ?
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8. 1.3- RE Processes: RAD (Role Actor Diagram). .
1.0 - RE BASIC PROCESS.
1.3- RE Processes: RAD (Role Actor Diagram). .
An RE Process is dominated by human, social and organizational factors
Cont..
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9. “What is an actor?” Is now addressed
1.0 - RE BASIC PROCESS.
1.3- RE Processes: RAD (Role Actor Diagram). .
“What is an actor?” Is now addressed
UML defines actors as “a coherent set of roles that users of use cases play when interacting with these use cases. An actor has one role for each use case with which it communicates”. We have the following problem with this definition: all entities realize a set of roles. So what is so unique to the actor? To understand the specificity of the actors, we need to consider how they are used:
Cont..
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10. An actor links use cases together by realizing a set of roles.
1.0 - RE BASIC PROCESS.
1.3- RE Processes: RAD (Role Actor Diagram). .
An actor links use cases together by realizing a set of roles.
An actor represents, in a use case diagram, an entity coming from another diagram (or vice-versa). Using the same name for an actor and an entity in another diagram establishes this relation
An actor may have a generalization relationship with another actor.
An actor represents entities that will not be further specified.
Cont..
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11. 1.0 - RE BASIC PROCESS.
1.4- IEEE Standard for SRS
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12. 1.0 - RE BASIC PROCESS.
1.4- IEEE Standard for SRS
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13. 1.0 - RE BASIC PROCESS.
1.4- RE in Agile Methods
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14. 2.1- RE Evolutionary Process
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15. 2.2- RE in Software Lifecycle
RE EVOLUTIONARY PROCESS.
2.2- RE in Software Lifecycle
an SDLC aims to produce high quality systems that meet or exceed customer expectations, based on customer requirements, by delivering systems which move through each clearly defined phase, within scheduled time-frames and cost estimates
requirements definition: Defines project goals into defined functions and operation of the intended application. It is the process of gathering and interpreting facts, diagnosing problems and recommending improvements to the system. Analyzes end-user information needs and also removes any inconsistencies and incompleteness in these requirements.
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16. 2.2- RE in Software Lifecycle
RE EVOLUTIONARY PROCESS.
2.2- RE in Software Lifecycle
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