When I first started to learn about Agile and Scrum, I learned about the User Story and I immediately asked, “Is a User Story the same thing as a Use Case?” I was told that it was not but the people I was talking to could not really tell me the difference. Therefore, I went online to do some research on User Stories. I also went to an Agile, Scrum, and Product Owner training. Everyone was talking about User Stories, but not a lot of people were referring to Use Cases anymore. I was a bit sad to learn that people were no longer advocating using Use Cases when I found so much value using them with my development team. As I continued on my agile journey, I learned that there are similarities between User Stories and Use Cases, they also serve different purposes, but they can still be used in conjunction with each other. There is still a place for Use Cases in Agile, but their use is a bit different.
Both User Stories and Use Cases identify users and user personas. They both describe the need or the goal. User Stories describe the value while Use Cases give you detailed steps and scenarios.
User Stories are used in agile to help breakdown features into sizable chunks, which can fit into a sprint. The purpose of the User Story is to describe the users or user personas, what they need, and why they need it. User Stories usually follow the format of “As a <user or user persona>, I want to <something>, so that <benefit>”. The User Story will also have Acceptance Criteria to confirm the user story.
Use Cases are often used in software and system engineering as a part of requirement definition. The purpose of the use case is to describe user or system steps of a process. Use Cases mainly consist of a Title, Description, Users or User Personas, Pre-Conditions, Basic Flow, Alternative Flow, Negative Flows, and Post-Conditions. Process Flows can be used to visualize the steps of the Use Case.
Even on Agile projects, I tend to use both User Stories and Uses Cases. I first develop Use Cases to understand the processes between the users and the systems. Uses Cases help me discover the beginning and end state of the process and different scenarios that may occur in that process. I then take my Use Case and create a process flow in order to visually represent the steps and flows. I create high-level process flows to describe the overall process and then detailed flows to show detailed steps, alternate flows and negative flows. I use the high-level process flows to write my high-level user stories (also known as epics). I then take my Epics, Use Cases, and Process Flows to the team to break the Epics into User Stories that will fit into a sprint. A User Story could comprise of one to several detailed steps depending on the sizing. A User Story could also be an alternate flow or negative flow.
On non-Agile projects, Use Cases and Process Flows are used in requirements document to define process steps between the user and system.
On Agile projects, Use Cases and Process Flows can be used to derive Epics and User Stories.
How do you use User Stories, Use Cases or Process Flow?