The internal auditors for Atlantic Enterprises, Inc. are auditing the purchasing function for the company's Northeastern region. One audit objective is to examine and evaluate the regional purchasing office's compliance with prescribed procedures for purchase authorizations. The audit team leader is considering the choice of audit techniques. The following are four possible alternative procedures:

1. Flowchart the prescribed authorization procedures from a policies and procedures manual.

2. Interview the regional purchasing manager.

3. Examine a sample of purchasing documents for prescribed authorization signatures.

4. Test all available documents for prescribed authorization signatures.

Required:

a. Identify key risks associated with evidence collected by each one of the above procedures.

b. How would using two or more different audit procedures decrease the risk resulting from only one audit procedure?