The emerging role of digital thread and digital twin

A GE wind turbine and its digital twin. (Image: GE Power & Water)

A new process model is emerging for creating and using product data

Despite a generation of talk about integrated manufacturing data, today the data behind most manufactured products comes from separate silos with names like PLM, SCM, and MES. I can’t tell you how many times I’ve heard someone describe their processes and say something like, “then we copy the data from the BOM.” The problem is, we have electronic documentation, but we don’t have digital workflow.

Now comes along Industry 4.0, a framework for describing how to best apply new technologies into both the manufacturing process and the product. Industry 4.0 is about making all data available all the time, including new data sources coming as we equip products to be part of the Internet of Things.

At GE, digital wind farm designers use a digital twin model residing in the cloud to build and optimize a real-world wind farm. (Image: GE Power & Water)

At the product data level, a new process model is evolving, where data is seen as part of both a digital thread and a digital twin. Both the digital thread and the digital twin are concepts, not specific products or services. You can’t run to your local integrator and order a digital thread.  Like using model-based engineering, the thread and twin describe a strategic framework for uniting data for maximum value in the enterprise. Both include as-designed requirements, validation and calibration records, as-built data, as-operated data, and as-maintained data.

The digital thread

The digital thread is the communications framework. It allows a connected data flow for all asset data through the lifecycle. “Digital thread” is shorthand for “the right information to the right place at the right time.”

The idea of a “digital thread” connecting engineering design with manufacturing started in aerospace almost 10 years ago. It was conceived by researchers at the US Air Force Research Laboratory at Wright-Patterson Air Force Base in Dayton, Ohio. The idea came from brainstorming a way to describe model-driven assembly on the factory floor. The goal is a digital manufacturing environment where data producers and data consumers all link to a common data source throughout the manufacturing process. Design, procurement, testing, production, field operations and sustainment all have access to the same data, without asking for it or copy/pasting from a separate database.

Ansys sees pervasive use of simulation as an important part of the digital twin concept. (Image: Ansys)

The digital twin

When all stakeholders have access to the same data, without intermediaries or bottlenecks, it becomes possible to use the digital thread workflow to create a rich representation of the product in virtual form, AKA the digital twin. The digital thread transmits a comprehensive view of the product which combines Bill of Materials details and CAD data; the digital twin is the resulting visual, virtual representation. It needs to be a two-way data flow, where validation, calibration, as-built, and as-used data is transmitted back to the digital twin. Together, the digital thread and digital twin are the unification of design and use.

In practice, there should be a set of expected methods and benefits. Each simulation run informs design and refinement. Each sensor on the product sends back data that informs continued development and guides operations. Depending on the product, there might be one digital twin that defines them all (like a mass market product), or one digital twin per product (like an aircraft).

The GE digital wind farm

Industrial giant GE is a leader in using digital thread and digital twin methods. Recently they shared how designed in their wind power unit created a digital model of an entire wind power farm.

“Every wind farm has a unique profile, like DNA or a fingerprint,” says Keith Longtin, general manager for wind products at GE Renewable Energy. “We thought if we could capture data from the machines about how they interact with the landscape and the wind, we could build a digital twin for each wind farm inside a computer, use it to design the most efficient turbine for each pad on the farm, and then keep optimizing the whole thing.”

GE calls the concept the “digital wind farm,” with two key parts. The first is a modular, 2-megawatt wind turbine that can be easily customized for specific locations (including a complete digital model). The second is software that can monitor and optimize the wind farm as it generates electricity. GE says that the technology could boost a wind farm’s energy production by as much as 20% and create $100 million in extra value over the lifetime of a 100 megawatt farm. The value comes from building a farm that matches the location, and then using data to produce, predict, and further optimize the farm’s performance.

Getting started

Most PLM vendors are working to integrate the digital thread & twin concept, but the successful creation of this process model will take some new plumbing, as it were, on the local level. Such issues as how the data will be accessed and used by manufacturing systems and services remains is still evolving.

Just as a business requires both a business model (for strategy) and a business plan (for execution) so also will engineering and manufacturing need to work closely on this foundational and necessary step into digitalization.

Randall S. Newton is Managing Director of Consilia Vektor.

More information:

Exploring the Digital Twin

Simulation for the Digital Twin Ecosystem

What is Digital Twin Technology, and Why is it So Important?

Keywords: digital thread, digital twin, Industry 4.0, BOM, PMI

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