Design and engineering moved firmly into the digital world several decades ago. Products of every description are drawn, dimensioned, tested, and defined in software and stored digitally – often these designs are never printed out on paper or manually manipulated in any way; it’s all digital from start to finish. Even documentation and user manuals are primarily digital these days.
Digital designs are passed to analysis programs for validation and multiple testing simulations and scenarios. The designs can also be digitally passed to machine tool programming software and the resulting programs loaded to CNC controllers for actually making the parts. The engineering side of manufacturing is quite well integrated and has been for years.
All of manufacturing is becoming more digital – from digital simulation of production processes and equipment, to product lifecycle management and predictive analytics to improve support and extend product life in the field. It is increasingly important to be able to exchange digital information between and among systems easily and reliably. The utility and value of digital data multiplies when the information can be passed electronically between and among systems throughout the manufacturing enterprise.
Exchange of data between systems has always been a challenge, since the early days of computing when systems from different vendors used unique data encoding schemes, different file structures and incompatible communications protocols. Most of that basic incompatibility has gradually disappeared as systems have matured and only a few common platforms and formats are now in use and communications protocols consolidated around the Internet and common protocols. We’re not there yet, however, at the application level. Specialized data such as that found in engineering files can still face difficulties when moving between systems, particularly when moving outside of the engineering and design world.
The National Institute for Standards and Technology, NIST has launched the Digital Thread project to “define and standardize standardized methods and protocols for exchanging and transporting information through design, manufacturing and product support processes to enable easy integration of smart manufacturing systems and accelerate the design to production timeline at reduced costs.”
NIST believes that it is uniquely positioned to address this need. It has extensive experience in the formal specification of geometries and tolerances, formal specification of engineering requirements, formal specification and simulation of manufacturing processes, formal specification of part quality requirements and measurement mechanisms. And NIST occupies a leadership position in standards bodies related to manufacturing and engineering.
According to NIST, “There are many gaps to be filled in the digital thread of information flowing from design to manufacturing and assembly, and to inspection. The manufacturability of a product can be very dependent on particular design parameters, both functional and non-functional. There is a design feedback loop between the design of the product and the design of the manufacturing processes. There are problems with effective communication from the part design tools to the process design tools, but the real problem is that there is no standard formal means of providing feedback to the designer. Similarly, the design engineer states the corresponding form and fit requirements for the components in terms of dimensions and tolerances. These are tightly coupled to design intent, but there is no formal means of conveying that intent to the part inspection systems, and there is no formal way to feed results of inspection back to the designer.” The NIST plan is to “apply systems engineering principles and emerging information technologies to specify mechanisms for capturing and communicating requirements, intent and feedback in a well-defined formal way.” NIST will identify missing information elements, model and codify the information elements, than publish the results to provide the technical underpinning for new standards.
When complete, the Digital Thread standards will enable engineers to design effective products, processes and systems in less time, and to communicate the requirements and details to manufacturing and to engineers involved throughout the product life cycle, including feedback to design.
Digital Manufacturing, a blanket term recognizing that all aspects of manufacturing (throughout the product lifecycle) are now highly dependent on digital data, becomes more of a reality when systems in various parts of the enterprise can freely exchange data without the need to convert, interpret or translate when crossing functional boundaries. Only then can we feel assured that the product descriptions, measurements, parameters and specifications are consistent, up-to-date and reliable.