Does the current Use Case Diagram clearly represent how users interact with the system?

Question

Detailed Idea for the Dermatech System

1. Main Idea of the System: Dermatech is an AI-based system that operates through a mobile application, designed to assist users in diagnosing primary skin conditions and providing treatment recommendations. The system aims to simplify access to initial dermatological diagnoses while reducing the need for doctor visits unless necessary.

How the System Works:

1. Image Capture and Disease Diagnosis:

The user captures an image of the affected skin area using their smartphone camera through the app. The image is sent to the application server, where a deep learning AI model analyzes it. The model identifies the potential skin condition based on the training data it has received.

2. Asking Additional Questions for Confirmation:

After the initial diagnosis, the system asks specific questions (e.g., itchiness, pain, spread) to verify the diagnosis. These questions are chosen based on a database containing symptoms related to dermatological diseases.

3. Providing the Final Diagnosis:

If the answers align with the initial diagnosis, the system provides the user with the final result and potential treatment recommendations (e.g., over-the-counter creams or medications). If the symptoms do not match the expected disease, the app advises the user to consult a dermatologist for an accurate diagnosis.

Answer 1

Use cases shall explain the purpose of the system independently of its internal structure and how it achieves in detail the purpose. It is also not advised to use a use-case diagram for functional decomposition (see also Ivar Jacobson article on the evolution of use cases).

Keep the use-case diagram focused on the goals, and move everything where a there is some sequential order required to an activity diagram that describes more in detail the behaviors behind the use-case.

All what you need for your question is above. nevertheless some hints to set in practice with examples:

• "View home page" is a user interface detail. Nobody uses a system just to see a home page.
• "Manage accounts" should appear only once, even if different actors execute it. The CRUD details are not necessary as they make it more complicated.
• "View past diagnoses" deserves a plain use-case on its own. Anyway, it's not included in "Manage account": this is an independent usage. Keep in mind: the fact that a user interface navigates from account to past diagnosis, is not a reason for the UC to show this user interface detail.
• Not sure that "Manage database" adds any value here.
• Login/logout are not use cases but actions that belong to an activity diagram.
• "Initial diagnosis" and "questions seem different steps in the "disease identification" and therefore better suited for an activity diagram describing the activity needed for the diagnosis.
• It is not clear if the autonomous AI actor also does the prescription or not. Depending on your design intent, either add it to the activity diagram of the diagnosis, or keep it as a separate use-case with a Doctor as actor.