UML Diagrams for Your Project Report: Which Ones and Where

Key takeaway

A project report usually needs seven diagrams: a Gantt chart and use case diagram in Requirements and Analysis, and ER, class, activity, sequence and often a data flow diagram in System Design. They must be consistent with each other and with your actual system.

The diagrams, and where each goes

Diagram	Chapter	What it shows
Gantt chart	3. Requirements and Analysis	Project timeline and phases
Use case diagram	3. Requirements and Analysis	Actors and what they can do
ER diagram	4. System Design	Database entities and relationships
Class diagram	4. System Design	Classes, attributes, methods, associations
Activity diagram	4. System Design	Flow of a key process
Sequence diagram	4. System Design	Messages between components over time
Data flow diagram	4. System Design	How data moves through the system

Tips for each diagram

• Use case: 2–4 actors, 6–12 use cases. Use include and extend only where they mean something.
• ER: show primary keys and cardinality (1:1, 1:N, M:N). Every table in your schema should appear.
• Class: match your real code: same class names, key attributes and methods.
• Activity: pick the most important flow (for example "place order" or "issue book") rather than drawing everything.
• Sequence: follow one request end to end: user, UI, server, database.
• Gantt: realistic phases (requirements, design, development, testing, documentation) with dates.

Consistency checks examiners make

1. Entities in the ER diagram exist as classes or tables in your design
2. Actors in the use case diagram appear in the sequence diagrams
3. The activity diagram matches the feature you demonstrate
4. Figure numbers and captions match the list of figures

Keeping diagrams editable

Text-based diagrams (Mermaid, PlantUML) can be edited like code, so updating them when your design changes takes seconds. The BlackBook editor renders Mermaid diagrams inside your report, and the AI Blackbook Maker generates the Gantt, use case, ER, class, activity and sequence diagrams from your project description. For captions and numbering rules, see the Blackbook format guide.