(c) Bruce Powel Douglass, Ph.D. 2019

Nov 20, 2018

Use Case/ User Story

2 comments

Edited: Nov 20, 2018

Dear Bruce,

 

in Harmony ESW process you added User Stories as an additional starting point to the Microcycle. I think User Stories are usually used to describe the "problem" or "expectation" of a stakeholder regarding the "product". It is maybe something like a high level requirements elicitation approach, which differs from Use Cases.

 

What are your experiences and best practices to work with User Stories (e.g. high level approach) and Use Cases (e.g. detailed approach) regarding high-fidelity modelling and requirements refinement?

 

Do you have a taxonomy regarding requirements, use cases, user stories and modelling?

 

Thank you.

 

Best regards,

Matthias

Nov 20, 2018

I just gave a workshop in India last week on this very topic. To my mind, a user story is equivalent to a scenario - a singular thread with perhaps minor variation. A use case contains several (typically 3-25) user stories. User stories have a canonical form "As a <role>, I want <feature> to achieve <goal>". As such, user stories are suitable for simple flows; more complex flows are better modelled as scenarios. Coherent collections of such flows constitute a use case. Both user stories and scenarios represent to a small number of requirements.

 

At the other end of the scale, use cases are sized to be implemented in a single iteration. Epics are like high level use cases that require multiple iterations for implementation. This is done by breaking the epic up into multiple use cases.

 

Does that help clarify it?

- b

Dec 4, 2018

There is a great post here: http://blog.hood-group.com/blog/2013/05/15/use-case-und-user-stories-verbundete-oder-feinde/.

Unfortunately, it is in German language. However, in short: An user story is an instrument to plan tasks in an agile development process. An use case contains much more architectural information and is used to model high-level views of interactions between the system to develop and the users/actors. An user story can be viewed as an use case slice which means the part of the use case which can be developed in one cycle.

New Posts
  • Is Agile methodology suitable for Firmware development? More generally, when Hardware and Software must be co-developed and manufactured, would Agile still be a good approach for the software development? Perhaps, Firmware can still be decomposed into an OTP (One Time Programmable) piece + a piece that can be updated "over the air", in which case the latter could still follow Agile. But what has been your experience with real Firmware projects? Thanks
  • I like the model organization structure that Harmony aMBSE is suggesting in Agile System Engineering, chapter 3.3 Organize Your Models Like It Matters. I have one question though: What is the reason that the Deployment View Pkg is in the subsystem models? That means that there is no holistic Deployment View (sometimes also called "technical context"), because the information is split over different subsystem models, right? I believe this view is especially important to integration and network guys. I also think that it is not a good idea to put a common Deployment View in the SE model as you do not want the dependencies to the physical interface packages there. I am wondering, does it make sense to keep a "complete" Deployment Package in the shared model? Please let me know what you think.
  • This forum is intended for discussions about processes and methods, focusing on agile and lean methods for systems engineering and embedded software development.