Introduction to Use Cases

What is a Use Case?

A use case is a description of a system’s behavior in response to external requests. It outlines the interactions between a user (or another system) and the system itself to achieve a specific goal. Use cases are primarily used in software and systems engineering to capture functional requirements.

Use cases help in understanding how users will interact with a system and can serve as a guide during the software development process.

Components of a Use Case

Use cases consist of several key components:

• Actor: The user or another system that interacts with the system.
• Goal: The objective the actor wants to achieve.
• Preconditions: Conditions that must be true before the use case starts.
• Postconditions: Conditions that must be true after the use case has completed.
• Main Flow: The primary sequence of steps taken to achieve the goal.
• Alternate Flow: Any variations or exceptions that may occur during the main flow.

Example of a Use Case

Let’s consider a simple use case for a Memcached system, which is a distributed memory object caching system.

Benefits of Using Use Cases

Use cases offer several advantages, including:

• Improved understanding of user requirements.
• Clear communication among stakeholders.
• Facilitation of testing and validation processes.
• Help in identifying system boundaries and interactions.

Conclusion

Use cases are a vital component in the development of systems, including software systems like Memcached. They provide a clear and structured way to capture functional requirements, ensuring that both developers and stakeholders have a shared understanding of the system's intended behavior.