Three vendors can each describe the same requirement as supported and mean something different by it.
That is the problem a vendor-controlled HRIS demonstration often fails to expose. Each vendor knows what is coming, prepares its strongest path and avoids the parts of the process where system boundaries become awkward.
Evaluators see polished screens and similar outcomes. They may not see where the core product stops and manual work, an interface or a third-party solution begins.
Take an employee who worked an overnight shift ending on Sunday morning. After payroll cut-off, the manager corrects the time record to include a call-out and a missed meal break. The change affects overtime, penalty rates, an allowance and cost allocation.
One product may manage most of that within its standard design. Another may need a separate award interpretation product. A third may leave payroll to calculate part of the adjustment manually and record the evidence outside the system.
All three can present a corrected amount on screen. The effort, dependencies and controls behind that result may be materially different.
Before demonstrations begin, define the evidence evaluators need about system boundaries, third-party dependencies, manual effort and exception handling. Then require each vendor to complete the same scenario and explain what is happening outside the screen.
The demonstration should give you enough evidence to understand what the organisation will be left operating after the implementation team has gone.