Do you use "scenarios" and "use cases" as one or separate?

  • There are a lot of discussions and information on the difference between scenarios and use cases, but I want to know how do they - or don't they - work together?

    At a high level, the main difference between a scenario and a use case as I understand it is that the scenario does not contain any of the technology or system interactions and is solely focuses on what the user (persona) is doing.

    So do scenarios and use cases both get created or is it ok to combine it into one?

    I have an assumption that they can help each other in building the valuable information that goes into both, but ultimately gets used for different purposes as in:

    Scenarios are used to inform design decisions and help with visualising the user's world more vividly during the design and development cycle keeping everyone focused on building the product for the user.

    Use Cases are used to inform business analyst and developers on the logical steps that need to be considered during the development cycle.

    Scenario from Wikipedia
    ...a fictional story about the "daily life of" or a sequence of events with the primary stakeholder group as the main character. Typically, a persona that was created earlier is used as the main character of this story. The story should be specific of the events happening that relate to the problems of the primary stakeholder group, and normally the main research questions the design process is built upon. These may turn out to be a simple story about the daily life of an individual, but small details from the events should imply details about the users, and may include emotional or physical characteristics...

    Use Case from Wikipedia
    ...describes the interaction between an individual and the rest of the world. Each use case describes an event that may occur for a short period of time in real life, but may consist of intricate details and interactions between the actor and the world.

    UPDATE: Based on the answer from Aadaam I thought I need to add more detail around the question to clarify what I am looking for.

    I understand there is a clear difference in a scenario vs a use case, but there are clear similarities as well. These similarities create confusion when you have a project that uses both.

    In the project I am referring to there are ux designers and business analysts. The ux designers rely on scenarios to convey the user's story. The business analysts rely on the use cases to convey the overall business, user and system requirements and functionality.

    So with that in mind - how and why would you use both during a project? Or is there a way that you can streamline by building the one and feeding the other?

    I have my own opinion on this, but first want to keep my biases out to get an objective answer.

    Some more additional information to provide clarity, special thanks to Aadaam for providing insightful answers around this topic.

    This information below comes from a course that I have recently gone to about user centered analysis in the ux research field

    Distinctions of Scenarios and Use Cases
    and how they may fit together in an orginisation

    • Scenarios are fully user stories

      • They do not reflect the system's activities (except as experience by the user)
      • Scenarios should be technology agnostic (as much as possible)
      • For example, "Jim views his current travel plan..."
    • Use Cases tend to be equally about the user and the technology

      • For example, "Jim views the home page, logs on with his user ID and password, and the system retrieves his current travel plan..."

    You can't have each separately: if your scenarios have nothing to do on how the system will be actually used, they're useless. If you don't detail scenarios for your use cases, your users can't reason about _how_ they want to use the system, your devs can't imagine it, and you'll end up with a product which'll behave like there was no UX made. A scenario is a plan of a use case (a plan for a solution), a use case is a high-level categorization of goals, needs and problems, and you need both in order to succeed.

    I agree that you can't have them separately. But I think they are two different deliverables that can support each other, based on the definitions as taught in the UX field. So would you agree that they are to be used differently? I've added these definitions to my question.

  • Adriaan

    Adriaan Correct answer

    9 years ago

    Doing more research around this topic I came across this article about User Stories, Use Cases and Scenarios.

    The article defines the three items, but more importantly at the end of the article it sums it up quite nicely, I think.

    Information below was written by Nadine Schaeffer.

    Scenarios

    Let’s start with scenarios. They are usually tied to personas and are part of creating a story about who the user of a particular technology is, what they want, what they know. A scenario is therefore usually written in narrative form, perhaps with pictures and illustrations as well. Scenarios are generally written at the beginning of a project during discovery and requirement gathering phases.

    Use Cases:

    Finally, let’s describe use cases. Use cases are generally written as part of detailed product requirement documentation. They capture the goal of an action, the trigger event that starts a process, and then describe each step of the process including inputs, outputs, errors and exceptions. Use cases are often written in the form of an actor or user performing an action followed by the expected system response and alternative outcomes. They provide human-centered anchors to guide design and development by providing tangible faces, names and stories for how the technology will be used.

    In Summary:

    Use cases, stories and scenarios are not interchangeable terms–each defines a specific process and set of deliverables. That being said, there are no hard and fast rules. It makes sense to review the needs of your project, what stage of development you are in, the skills and familiarity levels of the team, and then choose the user and task definition process that will work best for you.

    Update:

    I contacted Nadine Schaeffer, who wrote the article I refer to in this answer, around getting her opinion and thoughts about my question.

    I asked if I could share her feedback here which was a response via email:

    I use scenarios and use cases both for different purposes and at different stages in a project.

    I like to start a project with a personas and scenarios. In my mind, these two artifacts are closely tied together. Personas create believable archetypes of user types, and scenarios tell plausible stories about what these personas do. As a user experience designer, I tend to do the writing of personas and scenarios.

    Use cases, however, are less about people or personas, and more about what a product needs to allow a user to do. They are a user centric method of defining product features and requirements. Therefore, they are often written by the product manager.

    Nadine Schaeffer - Principal at Cloudforest Design and a user experience consultant professional

    Her answer has given me clarity and put my mind at ease around this question that has been bothering me for a while.

    I think "scenario" is being used for two different things: the scenario at the beginning of a project like you state; and the scenario as as the solution or implementation of a use case as Aadaam states in his answer. Find unique names for them (use case scenario comes to mind for the second meaning) and make sure you use them consistently.

License under CC-BY-SA with attribution


Content dated before 7/24/2021 11:53 AM