Final answer:
Auditors and systems analysts use systems documentation to understand, explain, and improve complex systems, not just for justifying investments, reducing external entities, or eliminating evidence.
Step-by-step explanation:
Auditors and systems analysts use systems documentation primarily to understand, explain, and improve complex systems. This documentation serves multiple critical functions. It enables the professionals to comprehend how the systems work, which is essential for processes such as auditing where verifying the accuracy of information is key. Furthermore, clear documentation can aid in identifying areas for systems improvement, providing insights into necessary changes or upgrades.
The notion that systems documentation is used only to provide justification to management for systems investments is restrictive and does not encompass all the purposes it serves. Additionally, systems documentation is not intended to reduce the number and amount of external entities, nor is it meant to eliminate evidence. Instead, it is a tool for preserving evidence and understanding interactions with external entities.
Similar to how models are used by scientists and how engineering notes can help with problem-solving and defending designs, systems documentation serves as a blueprint for analyzing and potentially refining business processes and systems. It is a form of organizational memory that can be critical during system audits, design changes, or in the event of system failures.