5 Reasons Why a Historian Can’t be the UNS

The concept of a Unified Namespace (UNS) has gained significant traction as a powerful solution for integrating and streamlining industrial data. While historians have traditionally played a key role in industrial data management, they simply aren’t equipped to function as a true UNS. If you're considering using a Historian as your Unified Namespace, think again. This post explores five key reasons why Historians cannot effectively function as a Unified Namespace, and how to properly integrate them into a UNS architecture.

1. Limited Event Handling Capabilities

Historians are primarily designed for storing and retrieving time-series data. They do not support change-based notifications or publish-subscribe events required for a UNS. A true UNS needs to support real-time data interaction and dynamic event handling across various applications.

For example, in a manufacturing plant, if a critical piece of equipment experiences a sudden temperature spike, a UNS should be able to immediately notify relevant systems and trigger appropriate responses. Historians, however, typically cannot support such change-based notifications or publish-subscribe events, making them inadequate for real-time operational intelligence.

2. Incomplete Data Integration

Historians were not designed for holistic data integration from the outset. Here’s why – while historians excel at storing process data, they often fall short in capturing the full spectrum of data required for a comprehensive UNS. The data collected by historians is often a subset of what's available from SCADA systems or PLCs. In some cases, historians do not collect all the data that is available through other data-gathering techniques. This limitation means that crucial information could be missing from the historian's records, leading to incomplete data integration. 

Consider a smart factory scenario where data from production lines, quality control systems, and supply chain management need to be integrated. A historian might capture production metrics but miss out on real-time inventory levels or supplier information, which are crucial for a holistic view of operations.

3. Lack of Open Architecture Support

Most historians rely on proprietary SDKs and API interfaces for data access, which goes against the open architecture principles of a UNS. With an open architecture, tools can be effortlessly integrated into existing data infrastructure, eliminating the need for specialized connectors or converters to handle proprietary interfaces. This streamlined integration accelerates the innovation process, as teams can focus on testing and developing ideas rather than navigating technical compatibility issues.

For instance, if an organization wants to integrate data from its historian with a new analytics platform, it might face significant hurdles due to custom engineering effort for each connection to the Historian or incompatible data formats. A true UNS, on the other hand, should facilitate easy data exchange using open standards like MQTT.

4. Challenges in System Adaptation and Expansion

Adding or modifying data sources in a historian-based system often requires substantial engineering effort. This rigidity contradicts the concept of a UNS, which should allow for seamless integration of new data sources and "self-aware" systems.

Imagine a manufacturing company acquiring a new plant with different equipment and control systems. Integrating this new facility's data into an existing historian-based setup would likely require significant reconfiguration and possibly new software licenses, whereas a well-designed UNS could adapt more readily to such changes.

5. Lack of Complex Data Models

Historians typically store data as simple name-value tags without much context. This approach falls short of the rich, contextualized data models required in a UNS. Historians often require users to sift through the time-series data and convert it into useful information, which can be time-consuming and error-prone. Whereas a UNS needs to be a store of modeled, contextualized, normalized, and transformed data ready for use.

In a modern industrial setting, data needs to be not just stored but also modeled, contextualized, and transformed to be truly useful. For example, a UNS should be able to represent complex relationships between different assets, their operational states, and how they interact within the broader production process – something that goes beyond the capabilities of traditional historians.

Integrating a Historian into Unified Namespace

While historians can't serve as a UNS, they still play a crucial role in industrial data management. The key is to integrate historians into a broader UNS architecture effectively. This integration allows organizations to benefit from both real-time operational intelligence and deep historical analysis within a unified data framework. Moreover, properly integrating historians with a UNS can enhance data accessibility, enable comprehensive analytics, and support more informed decision-making processes. It combines the strengths of real-time data handling with the power of historical trend analysis, creating a more robust and flexible industrial data management solution.

Conclusion

While historians are valuable tools for storing and analyzing time-series data, they fall short in meeting the comprehensive requirements of a Unified Namespace. From limited event handling to challenges in data integration and system adaptability, historians simply weren't designed to serve as a UNS. However, by understanding these limitations and properly integrating historians into a well-designed UNS architecture, organizations can leverage the strengths of both systems to achieve a more robust and flexible industrial data management solution.

As we continue to advance in the age of Industry 4.0, it's crucial to adopt technologies and architectures that can keep pace with the evolving needs of modern industrial operations. A true Unified Namespace, complemented by well-integrated historians, offers a pathway to this future.