As part of the implementation of a new payroll system, all transactions from the most recent actual payroll are processed in the new system prior to using the system to run payrolls. This is an example of what type of testing?

• A. Parallel
• B. Compliance
• C. Back-up
• D. Ongoing

Answer: (A)

Running the new payroll system in parallel with the current system using the same data is parallel testing. This approach lets you compare outputs from both systems for the same payroll period, ensuring the new system handles calculations, tax rules, deductions, and pay timing correctly before you switch over. It helps identify data conversion or mapping issues and gives you confidence that the new setup will produce the same results as the familiar, existing process.

Compliance testing would focus on regulatory requirements and legal rules, not on side-by-side validation of outputs. Back-up testing checks recovery and data integrity after a failure. Ongoing testing refers to continuous testing throughout deployment.