What is the composition of the customer service metric?
In an environment with many items and many orders, it can be calculated two ways: First a “line item fill rate” would be the percentage of individual line-items that were shipped complete, and on time within the month, for all items, all orders, etc.. Depending on the industry, some small tolerance may be set in both quantity and days, as long as that matches the expectation of the customers. Second, an “order fill rate” would measure the number of customer orders shipped complete, for every line item, within a reasonable date and quantity tolerance. This second one is a much tougher measurement, since if even one line item was on back order, it could affect many individual customer orders and cause them to be counted as incomplete, late orders. In environments with relatively few items and few customer orders, typically only the order fill rate is used.
