Learn to Love Diagrams
Visual representations are extremely useful for clarifying requirements in specifications documents. These visuals can be used for functional, technical, or detailed aspects and are known as UML diagrams. They make it much easier for anyone reading your document to understand its content.
UML (Unified Modeling Language) is a way of creating universal diagrams to represent IT systems.
Why is it important for a project manager to create diagrams?
Diagrams are essential for a number of reasons:
Understanding: They help you to understand the system you’re developing by breaking down complex elements into smaller, more manageable chunks.
Communication: They represent a common language for the various project stakeholders, improving communication and avoiding misunderstandings.
Documentation: They provide a visual form of the system documentation that can be referenced throughout the project.
Planning: Lastly, they help you plan and estimate the development work.
To create a diagram, I’d recommend you start by pulling together all relevant information and figures. With this data at your disposal, tools like Visio, Lucidchart, Draw.io, or Whimsical can help you create and structure your diagrams.
First of all, you’ll need to decide what you want your diagram to illustrate. Next, based on its purpose, you can select the most suitable type of diagram.
Select Suitable Diagrams
Sometimes, it’s difficult to understand a system.
Thankfully, there are various types of diagrams that can help us visualize and grasp the finer details of the system. Let me take you on a guided tour of some of these essential aids.
Use Case Diagram:
What is it? This diagram highlights interactions between the users (known as “actors”) and the system.
Why is it useful? It shows how the user sees and uses the system functionality.
Communication Diagram:
What is it? Also known as a collaboration diagram, this diagram illustrates the interactions between objects within a system.
Why is it useful? It provides a visual representation of how the different system components work together to accomplish a given task.
Activity Diagram:
What is it? It tracks the different steps in a process or task.
Why is it useful? It provides a high-level overview of the processes involved when the system is being used.
You might be wondering how to design these visual representations. Let’s take a more in-depth look at use case and activity diagrams. We’ve provided a video that will help you understand the creative process involved in producing them.
Create a Use Case Diagram
Do you want to understand how users are going to interact with your system and illustrate this with the most appropriate diagram?
I’d recommend the use case diagram.
A use case diagram is useful for helping you to understand the system functionality from the user’s perspective. It helps you focus on the actor who’ll be using your system by showing how they will interact with it. It’s an important step in ensuring that your system meets the users’ needs.
Here are two of the key elements displayed in the diagram:
Actor descriptions: The actors are the users of your system. They might be people, but they could also be systems or processes. By describing the actors, you’re defining who needs to use your system and why.
Application interactions: These interactions represent what the actors can do with your system. They help to identify the functionality that the system needs to provide.
A use case diagram presents three elements:
Use cases: A use case is a sequence of actions that an actor can perform using your system. For example, “Log In,” “Make a Reservation,” etc.
Use case success conditions: For each use case, you need to define what success looks like. For example, for the “Make a Reservation” use case, one success condition could be “The reservation is confirmed, and the user receives a confirmation.”
Relationships between actions: You can show how the different use cases link to each other. For example, a user must be able to “Log In” before they can “Make a Reservation.”
So, for each piece of system functionality, you can create a use case diagram. This will help you to visualize how each aspect of the functionality will be used and by which actor(s).
Here’s a demo of a use case diagram being created:
Following this demo, you’ll see more clearly how your users interact with your system. These diagrams are a real asset to improving user experience.
Over to You!
Background
You’re working as a project manager at AirGalaxy—a company that specializes in launching rockets. Your current role involves creating an application to manage rocket launches.
Instructions
Your task is to create a use case diagram using the Whimsical tool:
Draw the actors:
On the left hand side of the diagram, draw two stick figures to represent the actors. Label the first “Test Engineer” and the second “Simulation System.”Add use cases:
In the middle of the diagram, draw four ovals. Each oval represents one use case. Label these “Start Simulation,” “Stop Simulation,” “Visualize Trajectory,” and “Check History,” respectively.Connect the users to the use cases:
Draw straight lines from each actor to the ovals (use cases) they will interact with. The “Test Engineer” will need to be connected to all ovals, while the “Simulation System” will only need to be connected to the “Start Simulation” oval.
Produce an Activity Diagram
Are you looking for the most suitable diagram to visualize your system process flow?
I would recommend an activity diagram.
The activity diagram will be useful in helping you to understand the flow of tasks and their sequence within the system.
It’s an important step in ensuring that your system works seamlessly and logically.
There are many benefits of using an activity diagram:
A clear understanding of the system:
It helps to provide a clear view of how things operate and interact within the system. It’s a good way of documenting the important details so that everyone working on the project knows what to do.Structured documentation:
It also enables you to document the requirements in a structured way and becomes a useful reference for developers, testers, and other project stakeholders.
Here are two of the key elements displayed in the activity diagram:
Activity flow: The activities shown are specific tasks that need to be completed. By defining these activities, you’re creating a logical sequence of tasks to achieve a particular objective.
Decisions and conditions: These show the points in the flow of activities where a decision needs to be made. They help to define the possible paths through the system based on different conditions.
An activity diagram presents three elements: activities, control flows, and decisions:
Activities: An activity is a specific task that must be completed in your system. For example, “Choose Destination,” “Select Flight Date,” etc.
Control flows: For each activity, you need to define what will trigger the system to transition to the next activity. For example, once the flight date has been selected, the user can move on to “Choose Seat.”
Decisions: You can show where decisions need to be made within the activity flow. For example, a user might need to choose between “Pay Now” or “Pay Later” after selecting their seat.
So, for each process in your system, you can create an activity diagram. This will help you visualize how each task is completed and in which order.
Here’s a demo of an activity diagram being created:
Let’s Recap
UML (Unified Modeling Language) is an essential tool for project managers to help them understand, communicate, document, and plan IT systems.
Choosing the right type of diagram depends on your needs and the target audience. Use case diagrams are for user interactions, communication diagrams are for object interactions, and activity diagrams are for processes.
A use case diagram helps your audience to understand how users will interact with the system by describing the actors and their interactions with the application.
An activity diagram helps your audience to understand the flow of tasks within the system, including activities, transitions between activities, and decision points.
With your diagrams ready, let’s move on to creating conceptual data models. This diagram will help you clearly visualize relationships between different entities and structure your database efficiently.
