The review requested by the manager of the payroll department, focusing solely on the processes related to the approval of time worked, is best classified as a Compliance Assurance Engagement. This type of engagement aims to ensure that specific processes comply with established policies, procedures, or regulations - in this case, those related to payroll approvals. The emphasis on adherence to established guidelines and rules characterizes this as a compliance engagement rather than financial, operational, or risk management consulting.References: IIA guidance on different types of audit engagements.