The existing process
Businesses already rely on people who make mistakes. They make that arrangement dependable through training, access controls, responsibilities, checks and review. The relevant comparison includes those measures and the effort required to operate them.
A demand for error-free model output applies a different test from the one used to run the business. It can exclude an arrangement that would produce better completed work. Equally, the current error rate cannot justify preserving an existing control weakness. The required service standard remains the admission criterion.
Failure characteristics
Different systems fail differently. A mistaken mapping can affect many records, a model can produce a plausible unsupported explanation, and a reviewer can miss an error when the output looks familiar. A single average accuracy score conceals those differences.
The test needs comparable cases, defined failure severity and independent checks suited to the task. Serious access or execution failures need explicit acceptance and stop rules. The record should include errors corrected during the process, since those corrections consume capacity even when the final output is right.
Verification cost
Verification should require substantially less effort than execution. If the reviewer must obtain every source and repeat the investigation, the implementation has retained much of the work it was intended to remove.
The system needs to present the material evidence, calculations and unresolved discrepancies in a form the reviewer can use. A second model agreeing with the first is not equivalent to independent evidence. Nor is an approval click meaningful if the person lacks the information or time to assess the result.
Retained manual work
Where a tested system meets the required standard with less total effort, continuing to perform the same work manually has a measurable cost. There may be good reasons for doing so: an obligation, an unresolved failure mode, a limitation in the test or a consequence that requires a different form of oversight.
Those reasons should be stated. The fact that human failure is more familiar does not establish that it is less likely or less consequential. The comparison should determine the allocation of work, rather than justify a conclusion reached in advance.
Acceptance and scope
Evidence from one task does not confer authority over another. The firm approves the work, conditions and actions the system may perform. As performance improves, that scope should be reconsidered against the same service requirements, including the cost and effectiveness of the remaining supervision.
The aim is a more capable operation at an acceptable total cost. Permanent manual execution is a design choice with consequences, just as delegated execution is.