For several readers, arc42-section 1.1 will be the first thing they learn about the system.

Here you should express the business or project goals clearly and concisely. Give a brief overview of what problem the systems solves.

Note: Sometimes a requirements document relates to more than the single system that we describe in the architecture documentation.

If project scope and system scope are different, you should focus only the parts of the requirements that apply to this system.

Limit yourself to what is really important, the essence of the system.

Our rule of thumb:Less than one page, if possible. This page may contain a diagram if it supports the content. You should reference requirement documents if present.

Note: in some cases you probably need to write more:

• For systems with complex or extensive business requirements
• For systems without an existing (and reasonable) requirements documentation