Schneider Electric employs 125 people in Flint, Wales making PVC cable containment profiles for domestic and international markets. Production at the 8,000m2 site involves mixing and blending chemicals, producing pelletised PVC feedstock that is fed into extrusion machines on a number of production lines. Pull-off tables determine the rate and size of the extrusion. The material is further processed at sawing and punching stations. Once finished, the profiles are packed for distribution.
The site is more than 30 years old; as of 2019 much of the machinery was outdated and analogue. At that time site was the highest energy consumer of all Schneider Electric’s factories in the UK, and it was also a significant user of water.
But rather than close it, the company has a programme of digitising its factories to make them more efficient, explains John Flynn, UK & Ireland smart factory business development manager at Schneider Electric. “At some sites, we have the opportunity to build new, we can digitise the plant from day one; we are also able to do this with existing brownfield sites, changing them to become industry 4.0 smart factories, which is what happened at Flint.
“Schneider is a global company. Operating a factory in the UK, which is not a low-cost country, extruding plastic products that are easy to transport and lightweight, and which doesn’t require specialist input in materials and skills sets, could be shipped out somewhere low-cost, like the Far East. Part of this is about trying to avoid that, and make things here competitive with other parts of the industrialised world, like Europe and North America.”
The Flint transformation involved retrofitting the factory. To accomplish that, the first step in the process was to map all of the low-voltage plant on site.
Flynn explains: “Particular machines within the factory have low-voltage equipment, such as HMIs, PLC and variable-speed drives (VSDs) controlling the action of the machines. Auditing is about understanding what you have, where is it, how critical is it to the operation, what does it look like in terms of obsolescence.
“With Flint, there were various machines, in various lines, of various manufacturers, of different ages, at different levels of automation. If we have something on site that is critical, and if it’s obsolete, and we can’t get spare parts, and we haven’t any on site, there is significant risk if it does go down.” He cites as examples replacing and modernising PLCs, replacing control systems or getting spare parts on-site to mitigate the risk of breakdown.
Schneider’s industrial automation audit, which it brands IA3, enables technicians to look at and record what is in all of the control cabinets, map what spares are on site, and understand their criticality in a production context. Says Flynn of Flint: “For example, there is a gearbox on one of the pieces of equipment in the mixing and blending line. If that fails, the plant stops.” He describes the IA3 process: “Production and maintenance teams identify critical processes and spares availability, knowing the plant inside out. From that, the IA3 tool provides detail on obsolescence. We map out criticality, identify the business risks and what we can do to mitigate them.”
The team also investigated the electrical distribution system. Work was undertaken to digitise the single line diagram (SLD) with an intelligent digital model. This enabled the creation of a digital twin, to assist with fault finding during maintenance activities, root cause analysis and enable change modelling.
Flynn said: “As plants develop, different machines are added and different processes are put in place and changes are made to the electrical distribution system to accommodate that. Over time, you lose track of what’s been done. Then problems are difficult to fault-find. By digitising this, going around and recording everything, and putting it into software [ETAP, electrical transient analyser programme], you can create a digital diagram.
“Apart from covering the legal requirements, because it’s digital, and stored in the cloud, the right people have access to it; everyone has the same information. When the plant is updated, the record is updated so you can see what the changes are. This helps with fault-finding during breakdowns and with planned maintenance; trying to trace unmapped cables in existing factories is not easy.”
Having audited the plant, the company took action, modernising the existing LV installed base, before moving on to digital connectivity.
He continues: “We replaced outdated PLCs and VSDs, and in some cases where the machines were analogue, we removed the complete control system, and put in Schneider PLCs, HMIs and drives, so the machine was up to date and could be connected to the cloud via the Internet of Things.” Other machines were fitted with Schneider wireless, (and battery-less) magnetic sensors, for vacuum, temperature, humidity, current and voltage measurements.
The next step was to use Schneider AVEVA Plant SCADA software system to organise the growing network. The business development manager continues: “All of the machines are now connected within the two buildings in the factory. There’s a large display with everything that’s happening in real time, and anyone can raise an issue. Operators have an Andon button to call maintenance, to raise a quality issue or something else. That’s all displayed. There are no secrets. It’s very open, and that gives people ownership.
“A maintenance issue is not taken off of the board until it is resolved. All of the production team from the manager through to the operators has access to the same information. All operator stations have the same screens on each of the lines to see what’s happening in real time.” Flynn mentions that two other Schneider products were installed to provide system data: EcoStruxure Asset Advisor, Schneider’s cloud platform which provides monitoring and analytics of the electrical system from the power coming into site down to motor level, and Power Monitoring Expert.
Paper-based maintenance systems tend to be reactive, contends Flynn, and issues are recorded in hindsight; as a result, lessons are too often not learned. In contrast, “By connecting machines, we have improved maintenance, and we have a better understanding of the root causes of breakdowns. Modernisation has reduced the frequency of breakdowns we see; connected machines can tell us what is happening, often before it becomes an issue.”
In addition, an AR augmented digitised manual has been developed for each machine to make repair quicker and easier. He adds: “This is putting as much information as possible from manuals and circuit diagrams into a place where an operator has a smart tablet, can look at a machine, view photos of what it should look like, and use drop-down menus to open up the relevant information. You cannot completely get away from maintenance problem-solving, but it speeds it up. The smart tablet calls up information on the screen while you are pointing at a machine, to help understand what it should look like.”
Despite a 20% decrease in demand in 2020 due to COVID-19, Flint’s operational efficiency improved by 5% compared to 2019 levels, and productivity increased by 4% – the latter representing £240,000 in savings alone.However, the transformation also delivered a range of sustainability benefits. Improvements to efficiency associated with the installation of variable speed drives, smart panels, and other technological solutions reduced electricity (kW/h) usage compared to 2019. Flynn explains how that was accomplished: “There were current transducers and voltage transducers put in the control panels, monitoring the power supply through Power Monitoring Expert software. What we discovered with that was that there was an issue with the voltage from the supply side; we were able to monitor what we were doing, see what was happening and resolve the voltage issue [working with the electricity supplier]; that saved about 15% of energy because of that and other changes. And they weren’t aware the power supply was a problem until they started monitoring.”
And it reduced water consumption too, he says: “Although making PVC is a water-intensive process, we want to minimise its impact. It’s a scarce resource, even in Wales, and one that we have to pay for. When the system was backflushed, someone was supposed to check if the valves were shut weekly. If there was an issue, we were unaware; we were digitally blind. Then smart sensors and controls were fitted on the valves to see whether they were open or shut. With this and other initiatives, water usage halved from 2019 (4,228m3 previously; then 2,138m3).”
Flint was upgraded over 18 months from 2019. The modifications were all done in-house, with Schneider’s own equipment and drawing on controls and maintenance technicians from within the Schneider service organisation, after issuing an internal call for expertise. He concludes: “We can offer audits, SLD, looking at low-voltage equipment, cybersecurity, auditing, advising, pulling in experts to assist.”
BOX: Security in the digital factory
Manufacturers are at risk from increasingly sophisticated cyber-attacks such as ransomware and malware. While Flint was cyber-secure in general operations, it lacked policies and procedures to ensure safety across its newly-connected Internet of Things assets.
Schneider cautions that cybersecurity must come first in realising the benefits of increased connectivity and date-led automation. It says: “A comprehensive audit, based on the International Electrotechnical Commission’s standard 62443 and developed to secure industrial automation and control systems, must form the basis of this strategy. This should be paired with expert analysis to identify risks, prioritise gaps and recommend steps for remediation.” For more information, see also www.is.gd/ajileh.