CSE563 Lecture 02

Software Requirements and Specification
Concepts
(202201)

Transcript

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   CSE 563
   Software Requirements and Specification
   Lecture 02: Concepts
   Dr. Javier Gonzalez-Sanchez
   javiergs@asu.edu
   javiergs.engineering.asu.edu | javiergs.com
   PERALTA 230U
   Office Hours: By appointment
   

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   Requirements Engineering
   

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   Concepts
   necessities
   requirements
   

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   INVEST in good requirements
   § Independent – loosely coupled with one another
   § Negotiable – Stories are what and why , not how ( 99% ).
   § Valuable – for the customer!
   § Estimatable – Effort/Cost of design, build, and test.
   § Small (sized appropriately)
   § Testable – pass or fail
   

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   Concepts
   necessities
   requirements
   functional
   requirement
   non-functional
   requirement
   

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   Functional Requirement
   a) May state what (reactions, behaviours, or services) the system
   should not do.
   b) services the system should provide,
   c) how the system should react to particular inputs, and
   d) how the system should behave in particular situations.
   

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   Examples
   § Search option given to user to search from various invoices.
   § User should be able to mail any report to management.
   § Users can be divided into groups and groups can be given separate rights.
   What about
   • A video game?
   • Canvas?
   • MyASU?
   • Facebook App?
   

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   Non-functional Requirement
   Non-functional requirements
   a) Constraints on the services or functions offered by the system,
   such as
   Standards to apply, development platform, timing constraints,
   constraints on the development process, etc.
   b) Quality attributes, such as
   performance specifications, robustness, usability, etc.
   

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   Types of Non-Functional Requirements
   

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    Examples (Quality)
    Property Measure
    Speed • Processed transactions/second
    • User/event response time
    • Screen refresh time
    Size • Mbytes
    • Number of ROM chips
    Ease of use • Training time
    • Number of help frames
    Reliability • Mean time to failure
    • Probability of unavailability
    • Rate of failure occurrence
    • Availability
    Robustness • Time to restart after failure
    • Percentage of events causing failure
    • Probability of data corruption on failure
    Portability • Percentage of target dependent statements
    • Number of target systems
    

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    Examples (Constraints)
    § Should comply FERPA regulations.
    § Software is developed keeping downward compatibility intact.
    What about
    • Pac-man?
    • Canvas?
    • MyASU?
    

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    Questions
    

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    Homework
    § Read:
    Requirements Engineering: A Roadmap
    Nuseibeh, Bashar, and Steve Easterbrook
    Proceedings of the Conference on the Future of Software Engineering
    2000
    

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    CSE 563 Software Requirements and Specification
    Javier Gonzalez-Sanchez, Ph.D.
    javiergs@asu.edu
    Spring 2022
    Copyright. These slides can only be used as study material for the class CSE563 at ASU.
    They cannot be distributed or used for another purpose.
    

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