Organising processes properly from scratch is quite expensive for young IT-projects. Imagine two developers who started a project. At the start, they embraced all team roles. Their processes are simple, and they can share knowledge first-hand.
Once their project becomes successful, their team grows: new developers, testers and others. As a result, processes become more sophisticated too. But who knows how processes are organised? Maybe those developers who started the project? Not sure.
As the team grows and changes, the time comes to organise knowledge about the product into a single source - documentation. Where new team members can get answers why a particular process is performed that way and not another or how a feature works without review the code.
How to sum up everything and describe indescribable? How to create project documentation after the 10 years later from creating the project? A story about project documentation is a story about the role of a Systems Analyst in a team.