The <navigation system> should be able to <shall> <do something>

More details

• Why is this needed?
• What is the expected user interaction?
• What use case does this map to?
• Are there any non-functional requirements (build system, tools, performance, etc)

Example:

Warehouse Navigation

The navigation system should include a modular collision avoidance algorithm that can be replaced with a new algorithm at run time

More details

• I want to be able to write or use my own collision avoidance algorithm without having to re-compile the entire stack from source
• Ideally I can just change out a node using a custom launch file
• This maps to the "Collision Avoidance" use case