Work orders are a key part of every operation that is performed on the shop-floor. A world-class manufacturing operation is built from a series of smaller, individual manufacturing operations. The intelligence, and therefore the effectiveness, of a Manufacturing Execution System (MES) or Manufacturing Operations Management (MOM) solution is directly proportional to the capability of the work order infrastructure. More specifically, we mean work orders that are internal to the manufacturing organization, not commercial contracts between suppliers and customers. In fact, the basic definition of the work order is quite simple. It can be thought of as a group of many units of the same product that will be manufactured together in the same way. What was once a simple production job ID, is now a critical part of planning and execution of any PCBA operation. Understanding and using work orders effectively within an MES solution can reduce process setting errors, operational errors, quality issues, delivery delays, material and product scrap, while at the same time improve your floor’s compliance and traceability data with higher productivity. Understanding of the potential use of work orders is essential when choosing or working with an MES system in order to provide effective compliance, conformance and traceability.