What is a Use case?

 

A use case is a description of how a user interacts with a system or product. Companies build use cases to establish success scenarios, failure scenarios, and any important variants or exceptions. Below shown is a simple example of a use case diagram of Student Management System where student and teacher are the two users interacting with the system.

 

Use cases vary depending on your audience or system. The most important key components include:

·      Actor: anything exhibiting behavior that interacts with a system, such as a single user, a team, or another piece of software

·        System: the product or service with defined functionality

·        Goal: the purpose or objective users reach with a system’s features

Actors, systems, and goals build the foundation for a use case. Some of the key elements we should keep in mind while writing use case are:

·        Stakeholder(s): someone with a stake or interest in a system’s performance

·        Primary actor: initiates a system’s function to reach a goal

·        Preconditions: underlying factors required for the use case to take place

·        Triggers: events that begin a use case

·        Basic flows: use cases where systems work as intended to reach a goal

·      Alternate flows: different outcomes based on when and how a system veers off course.

Types of Use Cases

Use cases has two forms: business and system. A system use case is a detailed look at how users interact with each part of a system.

 

Business use cases show how a user might interact with your business to reach their goals. Instead of focusing on technical detail, it’s a cause-and-effect description of different inputs.

Steps for Writing a Use Case

Follow these steps when writing a use case

1. Describe Your System

2. Identify the Actors

3. Define Your Actors’ Goals

4. Create a Scenario

5. Consider Alternate Flows

6. Repeat Steps 2-5 to Compile Your Use Cases