Here is the direction that I would go in, for internal controls over purchasing:
The separation of duties for purchasing should be clear. All purchases that exceed a minimum should require authorization of three people. A main issue with companies this large is that large purchases can go unnoticed, which are ordered for employee personal use, to sell outside of the company, and for various other fraud schemes.
All new vendors should be verified against a master computer file (easily verifiable on the Internet) ...
In this solution, I help the student design a sample proposal for appropriate internal controls to cover purchasing and cash disbursements based on the Apollo Shoes case.