Enter The Digital Twin
A central idea to reduce complexity in all the key steps in the production process could be the Digital Twin. A Digital Twin is a virtual copy of something that’s modelled to behave realistically. We’ve aligned our Project Lifecycle Management (PLM) tools to provide a complete digital framework around which Digital Twins can be modelled to realistically replicate the product design and assembly processes – from beginning to end. So what does this mean? Using the same stages we discussed above, we’ve highlighted some of the key capabilities we think are most valuable in this approach.
Design:Using NX software (and other CAD systems), we can create a model of our product – and open them in Teamcenter as a 3D JT model. The software can virtually build literally thousands of variations of the product, just as it would be physically built, in seconds. It uses big data techniques, descriptions of the Product and Manufacturing and Information (PMI) that specify the product’s tolerances and components, and a basic description of the manufacturing process to determine if we have any clashes.
We trialled this approach on the design of one of our own electronics products. We were able to instantly see that the connector screws and corresponding video output connector holes had become misaligned. Unchecked, this could have resulted in warranty claims as the connector would separate from the PCB due to the manufacturing fault. Identifying design problems this early in the piece can save serious time and money – into and beyond the manufacturing process.
Process planning: The Digital Twin can improve collaboration between the design and manufacturing teams to better plan what needs to be made, how it should be made, the resources needed and where it can be made. Let’s take an example of an updated assembly.
Working with our tools, the planning team can use the new Bill of Materials (BOM) to input the new steps into a 3D working model of the current process. Production systems can be modelled anywhere, so a team in Paris can be planning production for a site in Rio. With time estimates available for the new processes, the team can see if the workflow will still ensure that the average unit product targets are met. If not, the revised or new cells can be moved up or downstream and a simulation run again until the sequence ensures that production targets are met. The revised plan can be easily accessed by all stakeholders and signed off. If there are any issues revealed during the process, the design and planning team can work together to rectify these.
Layout: With the floor layout, we recommend creating the Digital Twin – with all the mechanical, automation and resource details – and linking it to the product design and manufacturing eco-system.
Using a combination of PLM tools, the operation can be simulated by simply dragging and dropping cells, equipment and people into place on the line. It’s a very simple but effective way to design and make changes to the floor. So, if a product is changed and this requires the use of a new robot, simulation engineers can see if the robot’s size will, for example, interfere with one of the conveyors.
The layout engineer can then make the adjustment and issue a change request notifying purchasing that a new piece of equipment is needed. Furthermore, impact analysis can be run when changes are needed to avoid mistakes and inform any suppliers that might be affected. Process validation: With process validation, the Digital Twin can be used to digitally validate the assembly process. Intelligent modelling using quantitative analysis can assess all the human factors associated with the build to advise on issues such as working posture to help prevent employee fatigue and injury. The report can be used for training with videos and process guidelines produced for staff.
Throughput optimisation: The Digital Twin can also be used to statistically simulate and assess a planned production system. It can evaluate whether to use people, robots or a combination of the two. It’s possible to simulate all workflows – even down to the how much energy is utilised by the production equipment – tostreamline the process as much as possible.
The analysis can show how many parts will be produced by what process to ensure schedules are met prior to creating the physical line.
Manufacturing execution: Manufacturing execution can be improved by using the Digital Twin to close the loop between the physical and virtual worlds. Manufacturing instructions are released direct to the design floor where operators can view them along with associated videos.
Operators can feed back data from the production floor (eg: the gap between two panel screws) while other automated systems can also collect performance data. This can be used to assess if there’s any difference between the build designs and results to isolate and rectify any issues.
A New Way Of Doing Things
Using a Digital Twin, which replicates a physical product, can help spot problems more quickly to accelerate production and reduce costs across the production chain. What’s more, it ensures that the design can be made; the plan is always up to date and synchronised; the strategies will work; and production will perform as anticipated. It also helps to see how new technologies can be integrated into production lines without the risk of buying and installing them to see how they perform.
For one of the world’s most advanced industries, manufacturing has long relied on proven but dated approaches to planning its products and lines. The Digital Twin aims for a new approach to the way design, process planning and execution is applied in the manufacturing industry.
APMEN Sept 2016, Metrology & Design
