First, Design Engineering publishes the initial design or engineering changes for costing purposes and to provide a quote to the client. Next, design the main harness tooling drawing, and then design the production modules and subassemblies (sometimes requiring their own assembly boards). Next, engineers will design a Bill of Process (BOP) for the entire harness, distributing wires, solder joints, strands, and all remaining materials to designated equipment or stations. The BOP is then published to an enterprise resource planning (ERP) system. The final assembly line is then balanced and optimized, and operating instructions are created.