When an auditor accepts a printout from your system as evidence, they are relying on the system, and a software system audit is how that reliance is justified. The questions are not about features. They are about whether the right people can change data, whether a change leaves a trace, whether the trace can itself be altered, whether the system does what its written specification says, and whether it can be restored if it fails. A business that cannot answer those five loses the ability to use its own records as evidence, which quietly undermines every other audit it faces.
Access and segregation, tested from the user list outward
Take the full list of accounts with access, not the list of current staff, and reconcile the two. Leavers with live accounts, shared logins, and accounts with administrative rights that nobody can justify are the three findings that appear almost every time. Then test segregation: can the person who enters a record also approve it, and can the administrator alter data without leaving a trace. The answer to the second question decides how much weight any record from the system can carry, so it is worth establishing before anything else is examined.
The audit trail, and whether it is worth anything
An audit trail is only evidence if it records who changed what, when, and preferably why, and if it cannot be edited or switched off by the people it monitors. Test it by making a change in a test environment and looking at what the trail actually captured. Systems commonly log the fact of a change without the previous value, which makes the trail useless for reconstructing what a record said on a given date, and that reconstruction is exactly what an auditor asks for.
Validation: does it do what you said it does
Validation is the evidence that the system performs the functions your procedures rely on. It does not require a large formal exercise for most business systems. It requires a written statement of what the system is relied on to do, a set of tests that exercise those functions with real cases including edge cases, a record of the results, and a decision by a named person that the system is fit for its intended use. Re-run the affected tests after significant upgrades rather than treating validation as a one-time event.
Change control, backup and restoration
Changes to a system that holds evidence need the same discipline as changes to a process: a request, an assessment of impact, a test, an approval and a record. Backups need one extra thing that is almost always missing, which is evidence of a restoration actually performed. A backup that has never been restored is a hypothesis. Test one, record the date, the scope and how long it took, and that single record answers the audit question that otherwise turns into an uncomfortable conversation about business continuity.
Questions people ask about software system audit
Does a small business really need to audit its software?
It needs to be able to justify relying on the records. That is a short exercise for a handful of systems: who has access, what the trail captures, what the system is relied on to do, and whether a restore has been tested.
Is this the same as an IT audit?
No. An IT audit assesses the technology function and its infrastructure. This is narrower: whether the records a particular system produces can be used as audit evidence, which is a question for the business that relies on them.
What if the system is a supplier's cloud service?
The questions are the same but the evidence comes from the supplier: their access model, their trail, their assurance reporting, and your own configuration on top. Your controls over user administration remain yours to evidence regardless of where the system runs.
How often should the system audit be repeated?
Access reconciliation frequently, because it drifts with every joiner and leaver. The deeper questions on trail, validation and restore need revisiting after significant upgrades or migrations rather than on a fixed calendar.