Where is the edge of the data network, where compute power increasingly resides? This is the question industrial operatives are asking, as they look to combine advanced connectivity technologies and analytics techniques to bring new intelligence to their systems and processes. It is the question the Industrial Internet Consortium (IIC) is seeking to answer.
Away from the data centre, the cloud gets more nebulous than ever. Some digital way-finding is required, reckons the Industrial Internet Consortium (IIC). Its new white paper, entitled IIC Introduction to Edge Computing in IIoT, co-authored by Cisco, Huawei and SAP, presents an “industrial-grade cookbook” with recipes for edge computing in the industrial ‘internet-of-things’ (IIoT). It seeks to define an edge computing continuum, as part of the deal.
The industrial set needs help. On the one hand, it is already well practiced at running machine processes in software on-site. “They’ve been doing lots of logic processing, and things like that – in real time, for very specific functions, like making a chocolate bar or refining crude oil,” explains Lalit Canaran, vice president at SAP, and one of the authors of the ICC white paper. On the other, the need for real-time data processing, for critical enterprise systems, is high.
In manufacturing, the ‘edge’ has traditionally been the domain of an operations teams, in charge of SCADA and PLC systems in an industrial plant. “I don’t want to invent new terms on the fly, here, but in many ways that’s the ‘outer edge’, where everything is in real time – where the machines do what they were built to, and are orchestrated for that single purpose. We’re now seeing more gateways at the higher level, at the ‘inner edge’, where multiple lines talk with a gateway, and logic is running on more than just the one individual data point.”
The capability of industrial devices has increased, along with the power of the algorithms they feed into. Until now, this increased data-flow has required enterprises to connect up their operational (OT) and information technology (IT) to run analytics in centralised cloud systems. Edge computing, in conjunction with advancing connectivity and analytics, changes this, and provides multiple new methods to run these processes nearer to base camp.
“The market is developing multi-tier architectures to handle a range of compute requirements at various levels closer to the data source,” says Todd Edmunds, senior solution architect at Cisco and another of the report’s authors. These requirements for distributed intelligence are notably higher in manufacturing, he suggests. “There is more need for that horse-power at the edge. It changes the way we look at the cloud; its role starts to shift.”
Technical aspects
Which raises the complexity of the network architecture, and presents industrial companies, used to working one way, with certain challenges. Edmunds explains: “Most know how to do industrial automation, but they struggle with this new generation of devices and cloud computing, and putting all those things together. People are just throwing their edge-compute capabilities out there without a real plan or idea of how to manage it cohesively.”
This question, of where the edge is, has become urgent, as enterprises seeks to master the new technologies available to them. The IIC white paper makes clear the ‘edge’ is a logical layer, rather than a specific physical divide, and its precise location is up for discussion. “The answer is it depends on your use case,” says Edmunds. The describes a “continuum of fundamental capabilities” for IIoT solutions, and place the edge anywhere along it according to the technical requirements of the individual solution.
The business and usage viewpoints provide clues, while the functional and implementation viewpoints deal with the technical aspects. “There is no hard-and-fast saying that, ‘this is the edge’ – because you might be gathering and controlling data with an edge-compute temperature controller, and you might aggregate data in a single cloud instance from 35 factories around the globe, and then the edge becomes those factories themselves,” he says.
Indeed, the IIC’s four IIoT edge scenarios – at device level to measure pump temperatures, at plant level to monitor machine performance, at the factory perimeter to optimise supply chain processes, and at enterprise level to predict equipment failure (as described below) – are only a snapshot of a layered decentralised compute architecture
“The edge could be multi-layered. Some of those layers at the edge may look like many data centres at a big factory; it could start with something substantial like an oil rig, or something of that nature, and filter down to other smaller edges at a facility,” says Canaran. Compute power is being built into the connectivity layer, into the network itself as well, notes Hughes.
The white paper also contains a section about integrating with ‘cross-cutting functions’. The principle is to develop a “holistic” edge computing architecture, bundled with use cases and security models, that enable industrial companies to make better use of incoming IoT technologies. The report include use cases on safety management, fleet tracking, predictive maintenance, and product traceability.
The IIC will follow the white paper with a technical report, offering offer advice on the precise mechanics of industrial edge deployments. Commonalities will be brought to bear on IIoT use cases, to simplify the variety of edge placements. “No architecture will be exactly the same, but these similarities will mean [edge architectures] can be deployed with only minor changes,” says Canaran.
Technical challenges
The process of joining OT and IT environments, traditionally secured by ‘air-gapping’ the two realms, creates certain technical challenges and cultural panic, most notably with security. “The moment the IT guy drops in one of these new-fangled devices that connects to the cloud, you have to worry about security – and automation, and management, and patches, and everything else,” explains Canaran.
Compliance, security and privacy are considered in the white paper, along with discussion of certain other benefits of edge computing, notably the promise of improved performance and greater operational efficiencies. Do emerging protocols, notably the OPC UA over TSN stack, solve some of the security and privacy issues of IT-OT convergence? It is too simplistic a salve for such complex vulnerabilities, of course.
“There is no panacea for security. Security has to be built into each device and at every level of the architecture. It is not just one protocol, or one edge device, or the network. The computing and network endpoints have to be managed, along with the typical stuff – that patches are supplied, and networks are segmented to isolate and quarantine attacks,” explains Canaran.
Zooming out, the great challenge for the application of technology in the wide industrial sector is presumably its inherent, intractable fragmentation? For IIoT solutions to scale, their architects must surely be able to customise, and easily understand the customisation process? “Exactly, you nailed it,” says Edmunds. This is the point of the forthcoming technical report, which will seek to create order amid the necessary chaos of industrial edge computing.
The cloud computing paradigm has shifted, decisively, reckon Edmunds and Canaran, speaking on behalf of the whole industrial internet market. Centralised cloud resources are still good for industrial orchestration and aggregation, and high-level machine learning, but analytics is being pushed to the edge, and time-sensitive functions, whether for industrial machinery or autonomous vehicles, cannot be constrained by long connectivity loops.
“Someone said edge compute is the death of the cloud, but I don’t think that. It’s only the death of the cloud as we know it,” says Edmunds.
