5 Use cases

For each of the use cases, the OPC UA NameSpace needs to be known up front, before a connection to the physical machine (containing an OPC UA server) is possible. Therefore, the NameSpace for the machine needs to be available on the Internet on a global scale.

5.1 Configure the application behind the OPC UA Client which consumes the data from the machine

As a machine operator I want to configure the OPC UA Client and the applications behind, already very early in the development/procurement process of a machine or factory. The Cloud Library enables the machine builder to upload the NameSpace after final commissioning before the machine is shipped and installed in the factory. During this timeframe the application developer can finalize the development/configuration before the machine is online on the shop floor. Example: Online dashboard (“Cloud SCADA”) for condition monitoring, OEE calculation, predictive/preventative maintenance, etc.

As a machine builder I need to maintain a library/repository of all shipped machines and their respective NameSpaces. The Cloud Library enables such a storage and is also a versioning control system. Businesswise this reliefs the machine builder to operate and maintain such a repository for their own organization.

As a machine operator I could determine deltas in machine NameSpaces to identify and make use of new features of a machine. Therefore, I could browse the UpToDate model of this machine model to determine if available new features are useful for my operations.

The Cloud Library enables in this use case uniform processes for the whole shop floor machines. Additionally, I gain the time benefit between factory acceptance and final operation to develop and configure the applications which consume the OPC UA data.

The use of a Cloud Library in the context of auditing business process at the machine operator and machine builder’s organization enables an end to end reliable and well-defined process.

5.2 Specification compliance verification for new machines

As an OPC UA compliance certification authority I could use tools which are automating the NameSpaces certification of new machines by using the public Cloud Library as a unique uniform source for accessing the relevant type libraries.

As an equipment supplier I need to perform partial or complete NameSpaces compliance verification for a new machine tool which is integrating besides its own components, hardware/software from one or more suppliers either by aggregation or extension.

During operation and maintenance of a machine, the structure of the AddressSpace could change to reflect variations of the new replacing parts. As a process control engineer / maintenance technician I want to perform verifications of the OPC UA Server’s loaded AddressSpace against reference NameSpaces for troubleshooting or validation.

As a SCADA software engineer, I need to use automated tools to check compliance of new/replacing servers to client applications and vice-versa, report differences or support necessary re-adaptions.

As an automation integration engineer, I need to have a consistent up to date source of information about devices/manufacturers/suppliers which are conformant to a given companion specification/version.

As an equipment manufacturer/supplier I want to publish information about product releases conformant to a given companion specification/version as a way for creating product/brand awareness.

Structuring NameSpaces and associated metadata such that every nodeset is mastered (or edited) in only one place (single source of truth) and referred through unique uniform identification could enhance the engineering tools for automated IM compliance verification, with the final aim of reducing the overall systems engineering effort.

There could be two categories of compliance checks that are needed for all those use cases.

First check if a given model is compliant to the OPC UA specification in general (i.e., not violate any rules of how IM can be designed). This includes checks if known models (companion model or vendor specific) are used in a correct way.

The other kind of check would target the maintenance / update task. Find out if an updated model is backwards compatible to what is currently used. In other words, answer the question: The model changed, it is still compliant to the specification, but will my application and configuration still work? For example, adding a new subtype of an Object Type in a server still enables the client to continue working with the known super type. Other non-compatible changes would generate an error.

5.3 Retrofit OPC UA to existing machines

Brown field manufacturing systems may have embedded data models that aren’t articulated in a discoverable fashion but are likely derived from patterns or practices that have broad internal, or vertical industry acceptance – though without detailed implementation design. This “tribal knowledge” of how a piece of equipment or process works can be easily misinterpreted by different personas and runs the risk of getting lost entirely as a workforce shifts or turns over. Capturing these NameSpaces in a semantically reliable, structurally useful fashion, and publishing them for broad consumption, can allow manufacturers to map their systems to normative approaches found in a common library. Not only does this mapping accelerate future information projects on existing machines by providing a common interface and dictionary of terms, but it facilitates interoperability between systems, workforce development, and a reference implementation of industry practices that can be used to derive or develop new standards. A published library of NameSpaces that constituents can draw from enables implementers to begin to speak a “common language” that uses OPC UA as its lexicon.

Specific examples for this use case are:

As a Process Engineer designing a new line, I want to search for NameSpaces for Packaging Machines. I am familiar with PackML, so might search for that by name, or use terms from that standard.

As a supply chain participant for a consumer goods company, I’m required to implement an AddressSpace for my inventory management system that they have published to the Cloud Lib. I’d like to search for it by endorser and application (e.g.: warehouse, or logistics)

As a quality assurance engineer, I want to understand which Extruder OEMs have published NameSpaces about their inspection capabilities. I might search by vendor name, machine type, or quality terms I’m familiar with.

As a Production Manager, I’d like to find an efficiency NameSpaces I can retrofit into my paper converting operation.

As a Process Control Engineer, I would like to build my PLC program so that it fulfills a published NameSpace for a heat treatment process. I might search for “heat treatment” but I’ll also be interested to know if any existing Models have been built by or for my PLC hardware vendor of choice.

As a Machine Builder, I would like to understand what NameSpaces my customers might have found in the Cloud Lib to determine if I should implement my machine to support those models. I might search by industry, problem space, or even customer name.

As a System Integrator, I would like to retrofit the control program for an Automotive paint line, so that it meets the requirements of a newly published NameSpaces standard suggested by the Auto Industry.

As an AI Researcher trying to build a predictive energy model for smelting operations, I would like to search the CloudLib to see what NameSpaces the industry is using, so I can determine what data might be available for training my model.

Requirements for this use case include:

Comprehensive set of existing (standardized) OPC UA info models pre-set in UA Cloud Lib, logically grouped by machine type (can be a query API feature)

“Mapping Guide” for doing the actual mapping (can be supplied separately)

5.4 Downloading a NameSpace from the Cloud Library into a “blank” UA Server Instance

Abby works as an OT engineer at a steel welder machine manufacturer. For a new model steel welder that she is currently working on, her team has decided to map the proprietary information model provided by the machine to an OPC UA AddressSpace. Abby has learned that there is a vast online library of existing OPC UA NameSpaces out there, so instead of starting from scratch, she decides to base her information model on one of the existing NameSpaces, especially given the fact that her company has been using OPC UA for a while now and there have also been contributions to the Cloud Library. She goes online and quickly finds the Cloud Library main frontend website. She authenticates with the website and browses its metadata via one of the REST APIs. Within minutes, she finds the specific NameSpace that she wants to use in her “blank” OPC UA server built into the steel welder based on capability keywords that she has provided. There is also a preview of a subset of the NameSpace available directly on the Cloud Library frontend website where she can be confident that the NameSpace has the right information included for her. Building a machine OPC UA AddressSpace used to take weeks, now she can make it available for testing within minutes.

She acquires the license for the NameSpace she wants to use. She downloads the NameSpace in nodeset.json format and imports it into her OPC UA server via the standard OPC Foundation reference tools (e.g. “modelcompiler” tool).

After a few minutes, the OPC UA sever built into the steel welder is up and running and she can start browsing the newly created AddressSpace using a standard OPC UA Client application running on her laptop. She then starts wiring up data nodes to machine sensors and starts implementing the defined OPC UA Methods to control the machine.

5.5 Engineering support from existing NameSpaces

The use case of Jeff, a design engineer at a plant and machinery company, is similar to the before mentioned scenario of Abby, the OT engineer at a steel welder machine manufacturer. The difference is that Jeff needs to compose a new production line for his customer and many components of this production line are provided by suppliers who – like Jeffs company – deliver their machines and devices with NameSpaces. As these suppliers publish their OPC UA NameSpaces to the Cloud Library, it is a tremendous work simplification for Jeff, that he can – similar to Abby – find and download all relevant NameSpaces and merge them into the OPC UA server’s AddressSpace of the whole production line. Jeff will certainly also upload the resulting NameSpace to the Cloud Library, so that his customer can prepare the corresponding OPC UA Client and system landscape integration way before the new production line is physically installed at his customers premises.