Deloitte member firm outsourcing engagements are recurring in nature and comprise the performance of all internal audit activities including the annual planning, execution of the annual plan, and reporting to management and the audit committee. Under an outsourcing arrangement, the client may or may not have a chief audit executive (CAE) in place within their organization.

Co-sourcing engagements are recurring in nature and comprise the performance of some percentage of the total annual internal audit hours for an organization.

Subject Matter Expertise sourcing represents specific individual engagements where the client requires Deloitte's specialist skills and expertise to deliver internal audit services. Typically, Deloitte member firm professionals either conduct the entire project on behalf of the client or combine specialist resources with the client team to deliver the internal audit engagement.

The Institute of Internal Auditors (IIA) International Standards for the Professional Practice of Internal Auditing requires companies to conduct an independent quality assessment of their IA function at least once every five years.

Loaned staffed engagements represent the provision of internal audit resources that are under the sole direction of the member firm client – there is no Deloitte management oversight visible to the member firm client, no review of any working papers or other member firm client deliverables performed.

Internal audit transformation engagements represent assignments to assist an internal audit function evolve and transform to become more effective and deliver increased value. Areas of focus may include, but are not limited to, methodology, team matters, use of technology, and internal audit reporting. The buyer of these services may be the chief audit executive, management, or the audit committee of the board of directors.

Internal audit advisory engagements represent assignments to assist organizations with internal audit services not captured by one of the other highlighted solution areas. Services in this area may include, for example, general consultative advice or training.