Testing Physical Controls. Inadequate segregation of duties and the lack of effective supervision and independent verification can result in fraud and material errors. The exposure issues here are similar to the access control issues discussed earlier. Inappropriate access privileges are often associated with incompatible duties. Similarly, the purpose of collusion is to achieve unauthorized access to assets as well as the information needed to conceal the crime. In the absence of supervision and independent verification activities, errors and fraud may go undetected.