Throughout the year compare YTD customer sales with prior year YTD sales. For all of those customers noted lagging behind, ask the sales personnel to find out the reasons and what can be done to offset this loss. Is the customer foreign sourcing? Was there displeasure with some products or the company service? Were there problems with products? Are new competitors cutting into sales? Is your company experiencing too many late deliveries? What have been the customer complaints gathered from inside and outside sales personnel? Now is the time to find out these reasons from your sales personnel. If they cannot uncover the true reasons for this sales decline, you may need to begin looking for new staff.