When the auditor sets up his own records and processes them at the same time as the client processing data, he is using a technique in computer known as……………….

Parallel Simulation

Explanation:
Parallel Simulation is an audit technique where the auditor independently sets up and processes records concurrently with the client. This approach allows the auditor to verify the accuracy of the client’s data processing by comparing results in real-time, enhancing the reliability of audit evidence in a computerized environment.