Maker-checker
Prevent a preparer from approving their own payment when separation is enabled.
Payment control
Separate payment preparation, approval and posting so urgency never removes authority or evidence from the decision.
Where control breaks
The CostGrid control path
Prevent a preparer from approving their own payment when separation is enabled.
Recalculate approved net payable immediately before posting allocations.
Correct a posted allocation through a linked reversal with actor and reason.
Operational outcome
Start with one live project, keep the control trail intact, and expand only after the workflow proves useful.