A consulting engagement in internal auditing involves providing advisory and related client service activities, the nature and scope of which are agreed upon with the client. These are intended to add value and improve an organization's governance, risk management, and control processes. Helping in the design of the risk management program is a consulting activity because it involves advising management on how to establish or improve the processes for identifying, assessing, and managing risks. This is different from assurance engagements, which primarily focus on assessing existing processes.
Reference:
The Institute of Internal Auditors (IIA) Standard 2010: Planning
IIA Practice Advisory 2010-1: Linking the Audit Plan to Risk and Exposures