For those who aren't familiar with PlantUML, it allows you to describe a diagram in human-readable text, and then it displays it as a picture.
So, your text would contain code like this:
``` PlantUML
@startuml
left to right direction
skinparam packageStyle rectangle
actor Professor
actor Student
actor Staff
rectangle University-System {
Professor --> (Grade Exam)
Professor --> (Manage Course)
Professor ---> (Access Course Information)
Student ---> (Access Course Information)
Student ---> (Enroll in Course)
Staff ---> (Access Course Information)
Staff ---> (Manage Course)
}
@enduml
```
And that would give you a picture in Alexandria like this:
