Full Question
What is best method to evaluate a vendor's quality system?

Answer
It is essential to do a factory audit to review the QC system of your top potential suppliers in advance of placing a Purchase Order (PO). Depending on your budget constraints, you may choose to audit all the top candidates or perhaps just one or two. But it is essential to have some kind of on-site audit done. As the costs are generally hundreds of USD per audit when hiring a third party auditor, rather than thousands, I tend to audit the top four or five suppliers to give myself the best odds of finding that perfect match.