I am a Purchasing Manager, and I don't buy products. I buy value.
Value comes in many forms, but I have never found value by just looking for the lowest price. My company depends on me to seek out the best products from suppliers that are responsive to our needs, stand behind everything they supply, and can offer after-sale services that ensure their product is working right for our needs. When I find all of this at a competitive price – that's what I call value.
Dealing with multiple vendors means dealing with multiple purchasing agreements, multiple payment terms, and multiple vendor relationships. We have too many vendors. So vendor consolidation is important for me – when I can work with a single vendor that supplies a number of different products and services we use, that simplifies our purchasing processes and gives me "one throat to choke" if there is ever a problem.
When I receive complaints from my co-workers, it's usually because they can't get adequate support from the vendor that is supplying the product or service to us. Any vendor I work with must know their products, understand how to make them work for my company, and be available to answer our questions and provide the support we need.
We are always trying to streamline my department and make it more efficient, so make my buying process simple. I don't want to have to jump through hoops to buy products from my vendors. I have certain purchasing process requirements within my company that I must fulfill. Vendors need to work to my system, not me to theirs.