An important action by internal auditors to add value to their clients is to identify waste and inefficiency. In fact, the Institute of Internal Auditors (IIA) states in the Standards that acting with due professional care means identifying areas of waste:

Due professional care calls for the application of the care and skill expected of a reasonably prudent and competent internal auditor in the same or similar circumstances. Due professional care is therefore appropriate to the complexities of the engagement being performed. Exercising due professional care involves internal auditors being alert to the possibility of fraud, intentional wrongdoing, errors and omissions, inefficiency, waste, ineffectiveness, and conflicts of interest, as well as being alert to those conditions and activities where irregularities are most likely to occur. This also involves internal auditors identifying inadequate controls and recommending improvements to promote conformance with acceptable procedures and practices. Practice Advisory 1220-1 Due Professional Care