What is Complex Discrete Manufacturing?
Complex discrete manufacturing industries manufacture complex highly engineered products with longer product cycle times and multiple levels of subassemblies in their bills of material. Many of these companies make and engineer products to order. They make “discrete” product units, as in individually separate or distinct, and they need to track manufacturing history down to each serialized product unit. In contrast, batch production manufacturers track production per work center, day, batch or lot.
Complex discrete manufacturers include companies that manufacture products for aircraft, space, military weapons, complex medical devices, robots, and specialized industrial equipment. For many of these products it is necessary to manage complex diverse product configuration, long product life cycle, along with increased market pressure for shorter time to market for new products and stricter regulatory compliance oversight.
Some of the characteristics that define this type of manufacturing environment include the following:
- Long cycle times, low volume, make-to-order or engineer-to-order
- Complex product with deep bills of material (BOM)
- Highly skilled labor performing manual assembly and fabrication work including complex NC machines and special materials like composites
- Complex process routing sequences with decision points and loops
- High flow of engineering changes affecting work-in-process
- Production is not repetitive and mechanics must be alerted to changes
- Data collection during production includes manual data entry, verifications and signatures
- Personnel have qualification requirements and equipment have calibration and certification requirements
- Documentation requirements include complete history for each product unit and traceability of components installed and material used
Unique Requirements for Manufacturing Operations Management
On the surface, many manufacturing systems seem to have a similar functional footprint, but some cater to specific industries with very specialized functionality. To make an informed assessment of a manufacturing operations management (MOM) system it is necessary to drill down to more specific requirements and narrow down to the solutions that can truly handle your industry and type of manufacturing. Finding the right solution fit can hugely affect the effort, time frame, cost (total cost of ownership) and results of a MOM system implementation initiative.
Complex discrete manufacturing organizations have unique requirements in their manufacturing and quality management business processes including: (a) carefule resources certification management, (b) complex product/process configuration and change management, (c) detailed integrated quality control processes, (d) detailed product unit history and records archival.
Watchful Resources Certification Management
Personnel must be certified competent on the basis of education, training, skills and experience. Personnel qualification processes must be standardized and documented. In addition, equipment resources must also be maintained to assure their capabilities, especially measurement equipment used to verify the product. The equipment and tools maintenance and calibration processes must be standardized and documented. An MOM system can verify calibration status for equipment and also verify that personnel signing a job has the required active certifications.
Complex Product/Process Configuration and Change Management
The manufacturing of a complex product like an aircraft or satellite involves the management of a continuous stream of engineering changes directed at work in process. The integration of engineering systems and MES can create a seamless link between product development, manufacturing planning, and manufacturing execution functions that closes the loop on engineering changes and assures that as-built configuration matches as-designed.
Detailed Quality Control Processes
Beyond providing visibility into areas for improvements, the manufacturing information system should provide process control procedures to implement and sustain quality improvements including in-process inspection and verification steps, statistical process control (SPC), alerts to out-of-control conditions, and integrated handling for discrepancies found during production including defect containment and corrective actions to eliminate recurrence.
Because of the high investment in parts and labor that goes into these types of products, they are rarely scrapped. Instead, these industries require rework, repair and deviation handling procedures to ensure that deviations are documented, reviewed and approved by the appropriate personnel. The integration of production and quality systems can ensure that deviation instructions cannot be skipped by the mechanic performing the work. Deviation history is also considered part of each product unit history.
Detailed Product Unit History and Records Archival
The manufacturing information system needs to maintain production history documentation down to the details in each product unit versus tracking to the batch level. The system documents exactly who, what, when, how and why―who completed the job, what equipment was used, which parts were replaced, and who approved the changes.