For a while now the commercial world has been taking advantage of prefabricated classrooms, healthcare facilities, retail premises, and even hotels and dormitories. So why not a production line or factory?
According to ARC Advisory Group’s recent report on the market for DCS, the push to create COVID-19 vaccines significantly spurred the adoption of modular automation systems, not only in the life-science sector, but many other major process industries. To meet this need, adopting the latest generation of ‘single-point’ I/O, which can be either characterised individually with specific plug-in modules or configured using software, can pay real dividends.
These I/Os also make standard, modular cabinets and field enclosures, as well as remote instrument enclosures, more feasible.
The report’s key author is senior analyst Harry Forbes. He says: “DCS end users, particularly in the chemical and pharmaceutical industries, are increasingly investing in skid-mounted or modular systems. However, integrating the production controls and automation for a number of modular systems is becoming more cumbersome. Suppliers are addressing this issue by downsizing their controls and placing a mini DCS node on the skid-mounted system, allowing end users to integrate a bunch of nodes at the same DCS.”
Apart from the expense, the problem with this solution is that skid suppliers need to deliver a functional system, but often lack the knowledge of the 8-10 different types of DCS common in industry. As a result, they have to qualify and deliver their systems based on a particular automation solution.
MODULAR PRODUCTION
“The type of modular production we are talking about here is a related but separate area, which concerns capital equipment, and how you scale-up process plants by adding similar trains of modular units,” explains Forbes.
David Humphrey, director of research for Europe at ARC Advisory Group, takes up the explanation: “It’s known as numbering up. If you build a process plant, you scale it to the required capacity. However, if demand changes over time, while you might be able to run at 105% or 110% to get a little more output, eventually you’ll reach a physical limit. The next step is to build another process line or plant next to the original one, which is an expensive undertaking. This is where modularity can provide a realistic alternative. While a module-based solution may not perform quite as efficiently as a new-build line, it’s a lot quicker and cheaper. Also, you can both number up and number down to suit production requirements.”
Aside from skid-based systems and modular production lines, a third approach is building an entire plant from small modules. “We see this in some construction projects, where the design is modular with units constructed separately offsite,” says Forbes. “Some shipbuilders drive this approach to the extreme in the manufacture of large vessels. The difference is you are getting one large deliverable that is not designed for deconstruction, as opposed to a modular process line that can number up or down.”
AVOID MEGAPROJECTS
A modular process line is a permanent solution, representing a way to simplify and avoid megaprojects when they are not really necessary. Here, Forbes suggests that end users should consider adopting individually-characterised single-point I/O. “Much more hardware for remote locations is being delivered in cabinets that contain I/O, some switching and maybe some control gear,” he says.
“The value of these is that they are standardised ahead of the detail engineering. Each cabinet is sized by the number of I/O it can support. The supplier will use the I/O modules and characterisation modules, filling that in during the detail design phase when they know what field device/sensor/actuator is landing on a particular point. This strategy allows schedule compression, because after transporting the cabinet to the field, you begin the terminations and continue developing the detail engineering and software at the DCS supplier side.”
In short, the benefits of characterisable I/O go beyond simply reduced hardware, footprint and wiring. They allow end users to separate the hardware- and software-related aspects of the system to a far greater degree than was possible previously. It requires a lot of DCS engineering hours to assign specific I/O to a specific point in a cabinet and ensuring its association with a specific controller. In contrast, using fully adaptable and standard I/O and control hardware, end users can theoretically design and test all the software aspects of the system before deployment to the target system hardware. This strategy allows software integration with the hardware infrastructure at a very late project stage. Referred to as ‘late binding’, it becomes possible to compress capital project schedules, reduce risks and shorten time to production.
Fine chemicals and pharmaceutical sectors are thought to be the first targets of this modular approach. But Forbes adds: “However, I think it’ll end up being useful across the board in that all process industries are confronting far more difficulty than previously, with multiple systems integration tasks required as part of expansion or process change projects.”
BOX: WELL-CONNECTED
Among the facilitators of modular production is MTP (module-type package) technology, which in essence creates a deliverable on the module ready for interpretation by a higher-level system, known typically as an orchestrator. It is offered by ABB, among others.
Process plants can have pre-automated modular units, with each added, arranged and adjusted according to production needs. The MTP is a standardised methodology enabling interoperability between any module and orchestration system developed within the MTP framework. DCS is evolving to process orchestration systems that manage the operation of these modular units.
ABB’s module layer contains intelligent modules such as HMI, services for supervisory control, history, diagnostics and archiving. Within them, controllers from ABB’s Freelance range are implemented using MTP technology. The orchestration layer is a combination of operations and supervisory module control. ABB Ability System 800xA operates the process and orchestrates the intelligent modules, while an open architecture backbone links the orchestration layer to the module layer with communication via OPC UA. This building-block approach, which can scale up or down depending on production demand, targets pharmaceutical plants, biotech manufacturers, fine-chemical factories, and food and beverage.