What Is a Digital Thread?

A digital thread is the concept of using software tools throughout the lifecycle of a system to trace the interconnections of data and software artifacts. This digital thread is often a set of metadata that stores information about system artifacts and their relationships. It provides continuity of information from conceptualization through design, development, and deployment. By linking data from different lifecycle stages, digital threads provide a more comprehensive view of the system.

Why Digital Threads Are Useful

Using a digital thread provides advantages for product lifecycle management:

• Unified source of truth: Digital threads establish a single reference for all product data, ensuring consistency and accuracy. This approach minimizes errors and reduces the need for manual data reconciliation.
• Continuous data flow: By ensuring a continuous flow of information across all stages of the product lifecycle, digital threads eliminate data silos and reduce the risk of miscommunication or losing information.
• Informed decision-making: With real-time access to comprehensive data, decision-makers can make informed choices based on the complete lifecycle context of a product.
• Traceability and compliance: A digital thread enhances traceability, enabling precise tracking of changes and decisions. This capability can be crucial for compliance with industry regulations and standards.

Differences Between Digital Threads and Digital Twins

When discussing digital transformation, both digital threads and digital twins are relevant—but what’s the difference? While both are important tools, they serve different purposes:

• Digital thread: A digital thread provides connectivity and continuity of data across the entire lifecycle of a product. Its function is to ensure that data is preserved, enabling traceability that may be required for regulation compliance.
• Digital twin: A digital twin is a digital representation of a product, process, or system either in operation or in development. When in operation, it reflects the asset’s current condition and includes relevant historical data. Digital twins are used to evaluate an asset’s current state and, more importantly, to predict future behavior, refine control systems, or optimize operations. During development, the digital twin acts as a model of a to-be-built product, process, or system that facilitates development, testing, and validation.

Implemented together the concepts are complementary, with a digital thread providing the necessary data infrastructure to support the creation and operation of digital twins.

Digital Threads in Simulink

Engineers use Simulink^® to model, simulate, and analyze multidomain dynamic systems. They can develop digital threads by integrating system models and simulation data across their product’s lifecycle. They can create detailed system and subsystem models in Simulink that are part of the digital thread, ensuring that information about each part of the system is accessible and traceable.

Consider an example in which a team of engineers is developing a robotic arm. They start with a list of system requirements, such as speed of response and positional accuracy. The requirements are documented in Simulink, and they proceed to the design and development process. This is the first element in their digital thread.

The team develops the model, runs simulations, and refines parameters, logging data throughout the process. With each iteration, more data is added to the digital thread.

The system evolves, and the team creates test cases to validate it against the initial requirements. Each test is linked to the underlying requirement(s) and the relevant Simulink block(s). As the test cases are evaluated, more data is captured, documenting areas where the test passed or failed. The test cases and logs are now part of the digital thread.

When the system is ready for testing on the hardware, the team uses Simulink Coder™ to generate production code. Each portion of code can be traced to the Simulink block that generated it—another piece of the digital thread. The team deploys the code to a hardware target and continues to develop the system.

Throughout this process, the information in the digital thread within Simulink increases, interconnecting the requirements, components, data, test cases, and generated code. By establishing this continuity of information, the digital thread ensures that there is one source of truth for the system and that components can be easily traced to related elements.