I understand this situation. It can be quiet intimidating. No, you do not need to be an expert in the products but you need inputs to identify a product or process where there are more issues. You may try the following. Look for customer data - complaints, feedbacks, comparisons, unresolved queries, comments from lost customers, repeat customers, or any such information available. Look for workable metric among these. If reasons are known, try doing a pareto analysis for reasons. Speak to experts in marketing, sales, product development, version release, installation folks for 2 or 3 of the most selling or highest value products. Are there repeat issues faced by customers? Do they want some issues addressed to ensure first time right? If you are able to find main areas that can be supported by key people, you shall be on the right track. Hope this helps.