My Ongoing Journey to Discover the Unified Namespace

Like many others, I have been on a journey to learn exactly what the Unified Namespace is. Amidst the sea of content, there are so many definitions to get lost in. Some competing, some excessively abstract, and others just plain advertising. The only real consensus I have seen is in what it is not. Which doesn’t help as we are trying to nail down exactly what it is. I have spent a lot of time thinking and talking about the Unified Namespace over the last few years, consuming both paid and free content, and I think I finally understand.

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While doing a deeper dive into ISA95, I think I finally had my breakthrough on what the Unified Namespace is and how ISA95 fits into the concept. Including why the claim is that Part 2 is the only relevant part of the standard. I want to acknowledge that I might be completely wrong, though I think I have it down to a very simple definition. Before we get to that though, let’s walk through my thought process from the last few days that brought me to my conclusion.

The first observation that seems entirely too obvious is that the semantic Hierarchy is just the Hierarchy Scope as defined in ISA95 Part 2. This sparked a series of thoughts, connections I hadn’t yet put together that led me to the definition that I am writing this article about.

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Most every public example I can find of a Unified Namespace is primarily utilizing level 1 & 2 data with additive context as it travels through various consumers that themselves become producers. If we are calculating KPIs while modeling the data from machines, assets, and equipment, that is all accounted for in Part 2 between Equipment, Assets, Attributes, Properties, Personnel, and Materials.

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This data, the current state of it anyway, constitutes the Unified Namespace. Other nodes can connect through this hub, these nodes perform various functions including but not limited to control, visualization, data modeling, contextualization, storage, and analytics. Well other parts of ISA95 certainly contain relevant models, Part 2 contains the ones critical to the structure of a Unified Namespace. The rest are dependent on the specific application, the needs of the people that make up the organization that the Unified Namespace is made to represent. ISA88 can come into play pretty quickly here as well.

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Even the event driven and report by exception requirements that we often hear about are not technically required for the Unified Namespace. Those are requirements of the Digital Strategy that is often associated with Industry 4.0 and tightly coupled with the concept of a Unified Namespace. Thus, any modern Unified Namespace will need to be event driven and report by exception, but this does not exclude legacy implementations from being a Unified Namespace.?

Either way, let’s get to the definition.

A Unified Namespace is:

A Real-Time, Transient view of the Current State of the business. Using a semantic hierarchy, it provides a single, centralized hub for all nodes to connect through.

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This definition breaks down to 3 parts that we can break down even further,

1.????? A Real-Time, Transient View of the Current State.

2.????? Using a Semantic Hierarchy.

3.????? A Single, Centralized Hub for all Nodes to Connect Through.

The first part, A Real-Time, Transient view of the Current State, identifies it as a place where the current state of the business lives and travels through. Often times this is Key Value pairs, retained in memory as part of a messaging protocol. In MQTT it is Topics and their ?Values. This current state is structured in a way that is easy for both humans and machines to subscribe to, consuming and producing the data and information that they need.

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The second part, Using a Semantic Hierarchy, This is where ISA95 Part 2 really comes into play as the Semantic Hierarchy is just a simpler way of saying Hierarchy Scope. The same Hierarchy Scope that is defined in ISA95 Part 2. This is how we, and our machines, know where to find the data and information in a consistent and intuitive way.

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The third and final part, A Single, Centralized Hub for all Nodes to Connect Through, describes that the Unified Namespace is the central hub for the domain it represents. While it is a Single Centralized Hub within its domain, the Unified Namespace can be connected to other Unified Namespaces to create a Multi Hub network.

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Basically, a Unified Namespace is just a Transient Data Hub… With a few rules around context and structure. Multiple hubs can be connected to each other, resulting in multiple Unified Namespaces within an organization, or even joined between organizations to create an integrated supply chain.

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While a Unified Namespace does not explicitly use the entirety of ISA95 by default, it is certainly capable of supporting it. I will reiterate that I am not an expert on ISA95, I am still wrapping my head around the standard myself… but I will say that the more I learn about ISA95, and not just Part 2, the more the Unified Namespace makes sense to me. Hopefully my journey can help it make sense to you too.