01 May 2003
Bill of materials
The engineering bill of materials (eBOM) is the master product definition that contains "as-designed" information. In other words, the eBOM has context and instruction that allows manufacturing engineers to derive the manufacturing bill of materials (mBOM). They develop the mBOM by resequencing the eBOM in the context of the assembly process, and then derive the process information that will allow the new part to become production ready.
The resequenced eBOM is the mBOM, and the process information needed to build the product is called the bill of process (BOP). Additionally, the next generation manufacturing process knowledge management tools have come of age and are part of the PLM strategy. Optimization now occurs with PLM knowledge and results in build packages, which have the information for the MES to execute successfully.
ERP uses the mBOM and routing information derived from the BOP for product costing, resource planning, and scheduling. The MES (build package) also utilizes mBOM and a large amount of BOP information from the shop floor to execute the manufacturing plan. It is in this hand off between the eBOM (from the design systems) and the build packages into the business planning and execution systems that you can see the largest gains from integrating MES and PLM.
Traditionally, users reenter product design and process specification data into disconnected factory information systems many times to provide all the plant-floor systems with the data needed to build a product. Reentering data from one system to another is one of the main sources of production errors and quality issues, as well as work stoppages. Direct electronic transfer of data from a PLM system into a collaborative MES system becomes an important business requirement in today's manufacturing environment.
The chart above shows how the eBOM is created first, followed by the mBOM, and then manufacturing process data transfers to the MES for execution.
The chart below shows the proliferation of information that comes from the mBOM. This information originally comes from the eBOM. The benefit of managing the information in a single environment is that product and process data become reusable objects.
Source: EDS PLM Solutions