Author Topic: Requirements modeling and choice of element for interfaces  (Read 319 times)

mse

  • EA User
  • **
  • Posts: 101
  • Karma: +1/-0
    • View Profile
Requirements modeling and choice of element for interfaces
« on: July 09, 2019, 02:22:29 am »
The requirement element in UML is clearly the candidate obviously for modeling a requirement. However, what about when documenting the interfaces used in requirements. Currently, I use the requirement element as well, but sometimes I'm inclined to use interface or signal elements. Why would I use one or the other?

I think I should stay with requirement for everything because we have not decided on an implementation, because we are at the requirements level. Afterwards, a signal or interface would <<realize>> the interface requirement I documented.

Geert Bellekens

  • EA Guru
  • *****
  • Posts: 9392
  • Karma: +258/-27
  • Make EA work for YOU!
    • View Profile
    • Enterprise Architect Consultant and Value Added Reseller
Re: Requirements modeling and choice of element for interfaces
« Reply #1 on: July 09, 2019, 04:08:04 pm »
UML doesn't have a Requirement element. That is a Sparx invention.
We have used ArchiMate Appliation Requirements, and EA's own user interface objects (simple user interface thing) in the past to represent user interfaces.

Geert

natvig

  • EA User
  • **
  • Posts: 58
  • Karma: +7/-0
  • I love YaBB 1G - SP1!
    • View Profile
Re: Requirements modeling and choice of element for interfaces
« Reply #2 on: July 15, 2019, 05:08:13 pm »
You should look at SysML which is a UML based language (and an ISO standard) for modelling systems and its requirements. SysML includes all the concepts needed to model requirements and their relationships to system elements such as interfaces and other properties. The UML profile for SysML is available in Sparx EA.

Geert Bellekens

  • EA Guru
  • *****
  • Posts: 9392
  • Karma: +258/-27
  • Make EA work for YOU!
    • View Profile
    • Enterprise Architect Consultant and Value Added Reseller
Re: Requirements modeling and choice of element for interfaces
« Reply #3 on: July 15, 2019, 06:23:35 pm »
I thought SysML focused more on physical systems rather than software systems. Is that assumption wrong?

Geert

qwerty

  • EA Guru
  • *****
  • Posts: 10505
  • Karma: +231/-190
  • I'm no guru at all
    • View Profile
Re: Requirements modeling and choice of element for interfaces
« Reply #4 on: July 15, 2019, 06:51:57 pm »
That's basically true. But like UML can speak about soft- and hardware SysML can as well talk about hard- and software.

q.

Richard Freggi

  • EA User
  • **
  • Posts: 162
  • Karma: +7/-4
    • View Profile
Re: Requirements modeling and choice of element for interfaces
« Reply #5 on: July 16, 2019, 12:01:02 pm »
UML has very powerful ways to model requirements in use cases, interaction diagrams and class diagrams (attribute domain and associations).  There is no single requirement element in UML because that's how real life is: requirements are a type of constrain that can come from any different origin and impact any different element at any level (conceptual, logical, physical).  For example, TOGAF gets it right when it shows 'Requirement' phase directly impacting every other phase.
It does take some time to learn how to model requirements in UML but the payoff is big - definitely worth it.

natvig

  • EA User
  • **
  • Posts: 58
  • Karma: +7/-0
  • I love YaBB 1G - SP1!
    • View Profile
Re: Requirements modeling and choice of element for interfaces
« Reply #6 on: July 17, 2019, 05:49:17 am »
SysML is general in the sense that it can model any system, hardware and software. It can also be used to model logical architectures, i.e. where it has not yet been decided if solution is hardware or software. Yes, UML (and SysML) have diagrams suitable to model non-textual constraints/requirements in use cases, interactions, activities, state machines etc. However, stakeholder needs and requirements are still very often expressed in textual languages and you are often expected to provide traceability from those text based requirements to more refined model based requirements. This is where SysML comes in handy since it provides everything you need to make the transition and traceability from those text based requirements to other parts of your model. UML and SysML can be used together in a model. A suggestion is to add the requirements part of SysML to the UML you are currently using.

qwerty

  • EA Guru
  • *****
  • Posts: 10505
  • Karma: +231/-190
  • I'm no guru at all
    • View Profile
Re: Requirements modeling and choice of element for interfaces
« Reply #7 on: July 17, 2019, 07:21:13 am »
Actually it's quite simple to use native UML for doing that. However, when doing a large job I start with modeling requirements elements to fit the specific domain. Eventually I will adopt dialects (speaking from an UML view) like SysML to achieve that goal.

q