Simple System Architecture Diagram for BAs in draw.io
A business analyst does not need deep tech to draw a useful architecture diagram. Learn how to show users, apps, a database and outside systems in the free draw.io web app, and label every line with the data that moves along it, using an online shop.
Step by step
The big picture
- Architecture for BAs. A simple architecture diagram shows which systems a project touches and what data moves between them. You don't need to be technical to draw one. The example here is an online shop.
- Blank diagram. Start a blank diagram in draw.io. Every shape you need is in the General shapes.
Users and apps
- Users. Start with the people. Drag the stick figure (Actor) onto the page and label it Customer.
- Apps. Next, add the app the customer uses. A plain rectangle works for any system. Label it Shop website.
- Label the lines. Hover over Customer and drag the blue arrow onto Shop website. Label the line with what the customer does: browses.
- Apps. Behind the website sits the system that handles orders. Add a second rectangle and label it Order system.
- Label the lines. Connect Shop website to Order system, and label the line with the data it sends: orders.
Data
- Database. The orders need to be kept somewhere. A cylinder is the usual shape for a database. Put it under Order system and label it Orders database.
- Label the lines. Connect Order system down to Orders database and label the line order data.
Integrations
- Outside systems. Payments are handled by an outside company. Use a cloud for any system you don't own. Place it above Order system and label it Payment provider.
- Label the lines. Connect Order system up to Payment provider and label the line card payment.
- Apps. Last, add a rectangle on the right for the system that ships the goods, and label it Warehouse system.
- Label the lines. Connect Order system to Warehouse system and label the line pick list.
- Find the risks. Every line is an integration, and integrations are where projects slip. Order system has 4 lines (orders, order data, card payment and pick list), so start your questions there.
- The finished diagram. Click an empty part of the page to see the finished diagram. It shows people, apps, data and outside systems, and every line is labelled.
Recap
- The rules. The rules are simple. Use a stick figure for users, rectangles for apps, a cylinder for data and a cloud for outside systems. Put a label on every line saying what moves along it.
Common mistakes
- Lines with no labels. An unlabelled arrow only says two systems are linked, not what passes between them. Label every line with the data it carries, like orders or pick list.
- Using the same shape for everything. If the database and the payment provider are both rectangles, readers can't tell what you own from what you don't. Keep to cylinders for data and clouds for outside systems.
- Lines that aren't attached to the shapes. If you let go of an arrow near a shape instead of on it, the line won't follow the shape when you move it. Drag the blue arrow right onto the target shape so it connects.
- Adding too much technical detail. Servers, ports and protocols make the diagram hard to read in a business meeting. Show users, apps, data and outside systems, and leave the deep detail to the technical team.
When a business analyst uses this
In a discovery workshop for a new checkout change, a business analyst draws this diagram live with the team. Each labelled line, such as card payment to the payment provider, then becomes a row in the RAID log or a question for the integration owner before requirements sign-off.
Questions people ask
Is draw.io free to use?
Yes. draw.io is a free web app, and you can start a blank diagram in your browser without paying.
Which shape should I use for a database in an architecture diagram?
Use a cylinder. It's the usual shape for a database, and you'll find it in draw.io's General shapes.
Do I need to be technical to draw a system architecture diagram?
No. A business analyst only needs to show who uses the system, which apps and databases are involved, which outside systems connect to them, and what data moves along each line.
