Creating a Use Case Diagram (UCD), A Breakdown of the Process

A Use Case Diagram (UCD) is a powerful tool in product development for visualizing user interactions with a system. This technique is valuable because it has a structured way of showing technical and non-technical teams a simplified explanation of the tasks users intend to carry out on a product.

The Importance of Use Case Diagrams in Product Development

1. Documentation and Reference

UCDs serve as a valuable documentation tool, providing a clear reference point for the system’s functionalities and user interactions throughout development.

2. Improved Communication

UCDs provide a common language for technical and non-technical stakeholders. This fosters clear communication about system functionalities, user goals, and workflows.

3. Promotes a User-Centric Design Process

By depicting user interactions, UCDs ensure the development team keeps the user at the center of the design process. This helps create a product that caters to user needs and expectations.

4. Early Identification of Issues

UCDs can reveal potential usability problems or gaps in functionality early in the development cycle. This allows for course correction and avoids costly rework later.

5. Prioritization and Planning

UCDs help product managers prioritize features based on their importance to user goals. This facilitates better planning and resource allocation during development.

Who Creates a Use Case Diagram?

In product development, Use Case Diagrams (UCDs) are typically spearheaded by Product Managers. Their deep understanding of user needs and product functionalities allows them to define the user interactions the UCD will represent. This fosters clear communication across technical and non-technical teams, keeping the user at the center of the design process from the start. Designers, developers, and user’s input are also needed when creating UCD.

The Components of A Use Case Diagram (UCD)

Creating a UCD is much easier when you understand the components and what each represents. We shall examine each component one after the other;

1. Actor

Actor Symbol

In a Use Case Diagram (UCD), an actor isn’t a person like a movie actor. Instead, it represents an external entity that interacts with the system. This can be:

• A user: This is the most common type of actor, representing a person who interacts with the system in different roles (e.g., customer, administrator).
• Another system: If your system interacts with another software program, that program can be an actor in the UCD.
• External factors: In some cases, even external factors like timers or sensors that trigger actions within the system can be considered actors.

2. Use Case

Use Case Symbol

Typically represented by an oval shape, use cases are the features or functionalities the system offers its actors. It can also be viewed as actions triggered by an actor.

Examples of use cases for a grocery app can be;

• Browse groceries.
• Search and filter results.
• View catalogue and add-to-cart.
• Make payment.
• Track order/view order status.

3. Relationships

Relationships symbols

In Use Case Diagrams (UCDs), three main relationships help depict the interactions between actors and use cases:

• Association: This is the most fundamental relationship and represents a simple interaction between an actor and a use case. The symbol connects actors to use cases. For example, in the Opay Payment app UCD, a “User” actor will have an association with the “Make payment” use case.
• Include: This depicts the essential connection between the functionality of one use case to another. It’s like including a subtask within a larger task. The symbol is an arrow labeled “include” points from the primary use case to the included one. In the Opay Payment app UCD, the “Make payment” use case might consist of a generic “Login” use case common to other functionalities.
• Extend: This shows an optional or alternative connection between use cases. It’s like adding an optional branch to a program’s flow. An arrow with the label “extend” points from the base use case to the extending one, along with a description of the condition that triggers the extension. In the Opay payment UCD, the “Make payment” use case could be extended by a “Use Cashback” use case.

Creating A Use Case Diagram; A Breakdown of the Process (Using Uber Eats as a Case Study)

We’ll carefully examine the step-by-step process of creating a UCD using the UberEats app as an example.

1. Step 1: List all actors involved in the UCD and its components. The actors required to interact with the app are listed below.

• Users: Customers who want to order meals on the app.
• Delivery driver: The users offering delivery services to customers. They will pick up the meal from the restaurant and deliver it to customers.
• Restaurant: Food suppliers on UberEats.
• Admin: Uber system admin overseeing activities on the platform.
• Payment gateway: The payment system is integrated into the app to simplify payment processing.

2. Step 2: Identify the possible use case each actor can trigger on the app.

3. Step 3: Arrange the use cases in the oval symbol and place them in the rectangle.

Also, the actors responsible for the use cases should be placed outside the box.

4. Step 4: Connect the actors to their use cases (relationship by association)

5. Step 5: Show the include relationships (the relationship between each use case)

Remember that for Use Case 2 (for example, “view order history”) to be active, Use Case 1 (“Order food”) must have been triggered.

6. Step 6: Show the extended relationships; these are optional or alternative use cases

For example, payment can always be processed without a coupon, so the “Apply coupon” use case is an extended relationship.

Endnotes

In conclusion, Use Case Diagrams (UCDs) are valuable for product development. They provide:

• A clear visual representation of user interactions with the system.
• Fostering communication.
• Promoting user-centric design.
• Aiding in early issue identification and prioritization.

By understanding the components (actors, use cases, and relationships) and the step-by-step process of creating a UCD, you can leverage this technique to design and develop products that effectively meet user needs.

Using the example of an UberEats UCD, this breakdown has provided a clear understanding of how to leverage UCDs to create a blueprint for successful product development. UCDs are a collaborative effort, and input from various stakeholders can enrich the process and ensure the final product aligns with everyone’s expectations.

Thank you for reading, see you next time!