1 / 8

Requirements Engineering

Requirements Engineering. Requirements Engineering. The first step of each process model What do we want to build?

gali
Download Presentation

Requirements Engineering

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Requirements Engineering

  2. Requirements Engineering • The first step of each process model • Whatdo we want to build? • They may range from a high-level abstract statement of a service or of a system constraint to a detailed mathematical functional specification: can be statements (“The system shall…”), diagrams, use cases, etc. • Can be used as basis for contacts, etc.

  3. Requirements specify external behavior • Functional requirements are statements of the services that the system must provide • “The system shall display the heart rate of the patient” • Non-functional requirements are constraints on the services and functions offered by the system • “The system shall display the heart rate of the patient within two seconds” • Performance, Scalability, Capacity, Availability Reliability, Recoverability, Maintainability, Serviceability, Security,
Regulatory, Manageability • Exercise: list some functional and non-functional requirements for an iPhone

  4. Requirements qualities • Three Cs: • Clear • Consistent • Complete (internally and externally) • Use the SE principle of incrementality to derive requirements • Remember, they must all be externally visible • Why? They must all be testable

  5. Testable Requirements • Do not use vague terminology; “errors shall be minimized…” • Should NOT partially pass or fail • Should have a source

  6. In-class example • Let’s imagine we have an ATM • Come up with 5 functional requirements • Show how each requirement could be improved • Show how each requirement could have been worse • Come up with 3 non-functional requirements • Do the same as above

  7. Requirements Validation • It’s cheapest to fix faults at this step, than later on (sometimes 100 times cheaper) • Are they testable? • Do any conflict? • Do they cover all aspects of the system? • Are they what the customer wanted?

  8. Assignment • Examine the Quiz Game description • In your teams, come up with at least seven functional requirements and at least two non-functional requirements • Remember the three Cs • Requirements specify external behavior • Requirements must be testable • Turn in this assignment through XP-Dev • See instructions and grading rubric on project page

More Related