A supplier's quality management effort to meet your existing contractual requirements is broadly reflective of their overall approach to quality, which is assessed through various kinds of audits. A product audit ensures that the final product meets the specified requirements, a process audit examines the processes to ensure they are capable and effective, and a system audit evaluates the supplier's total quality management system. Thus, it is accurate to say that it involves a product audit, a process audit, and a system audit.