Why a system is bound by a decade-long lifespan.
One of the most important considerations for new and updated monitoring and control applications is scalability. The question is: once a significant investment is made, how do end users get the most return on their investment? Or more simply put, how long will the system last?
Chris Little, Media Relations, VTScada by Trihedral, talked with Control editor-in-chief Len Vermillion as they wondered, what if a SCADA system could last 100 years?
Q: First, why 100 years?
A: It’s a bit arbitrary. It’s not like we wouldn’t want them to last 200 years. I just wanted to offer an alternative to the unspoken assumption in the automation industry that your new SCADA system, if all goes well, will last about 10 years. Basically, when the time comes to replace PCs, many users will simply rip out the whole thing and make a brand-new application.
When you start with that 10-year lifespan in mind, it leads to all sorts of decisions that not only affect longevity, but also the usability of the system during that lifespan.
Q: If an end user doesn’t want to go through this process again in a few years, what should they do first to end up with a ‘100-year’ system?
A: The first thing is to ask your consultant or integrator, or your own OT department, “How many third-party software products will need to be cobbled together with script code to provide the basic functionality we require?”
Anyone who’s used a third-party alarm notification product with their SCADA system has had to deal with the challenge of ensuring that they can still work together properly after 10 years or more of numerous software or firmware updates. What happens if one of those third-party components is discontinued? Over the last few decades, we’ve seen multiple scripting languages come and go. What if the pricing model on your third-party historian product is no longer desirable?
End users want to choose a SCADA platform where all the core functionalities are built in, including the historian and the communication drivers. This is one of the most common ways that SCADA applications grow old before their time. It’s also why we chose to develop and maintain every part of our VTScada software. Each time you update to the latest version of the VTScada software, every critical component continues to work in lockstep.
Q: What are some other ways SCADA systems age prematurely?
A: They rely on custom coding. End users are often sold based on the idea that they can get exactly the system they want by cobbling together native and third-party components using script code. Many Integrators like this approach because they’re good at it and it’s fun. The question is, what do you do five or 10 years down the road when you need to expand or troubleshoot this code, and the person who wrote it is retired or working somewhere else? Once again, the more custom code, the more difficult it can be to upgrade to the latest version of the SCADA software or the operating system.
So, the best way to ensure your system will last is to choose a platform in which your core components like logging, trending, reporting, alarm management, mapping, version control and so on are all pre-configured out-of-the-box. We designed VTScada with this in mind. You can still customize the parts that are truly unique, but all the standard stuff is ready out-of-the-box. Plus, the more custom code there is, the less likely you are to make the updates you need to keep your system young and secure.
Q: Does everybody want to keep updating these systems?
A: Good point. Once a system is completed and commissioned, it’s common to manage these issues by locking their servers in a box with no access to the Internet. Don’t touch it. Don’t update it. Don’t look at it. That means no new features and no security updates to the SCADA software, operating system or even the physical server itself. That can work in the short-term, but it means no bug fixes, no security updates, and no new features to help adapt to your changing needs. Also, that locked up server will just keep getting slower.
It’s also a myth that an offline server is inherently secure. We’ve all seen headlines about “spear phishing” campaigns, where individuals who work on these systems are quietly targeted with sophisticated malware that just waits for someone to bring their work home. If your server is running an unsupported operating system that’s had no security updates in years and a version of the SCADA software with known vulnerabilities, locking it in a room isn’t going to keep you safe in the long-term.
Q: How else can end users make it easier to keep their systems up to date?
A: Run more than one server. If your system is mission-critical, then this is already a no brainer. There’s no better way to built resilience into your application, especially if the servers are geographically separated. VTScada is the only platform that supports any number of redundant servers. But, in addition to providing automatic hot backup failover, two or more servers make it easy to update the different parts of your system without downtime.
We designed VTScada to make this process easy. As you take each server offline for updates, the system simply fails over to the next designated server in the server list. When the updated server is restored, VTScada automatically synchronizes it with all the historical data it missed.
Also, VTScada uses multiple servers to help keep your system feeling young by distributing the load of various processes across different servers. Server A can be the primary logging server for Site A and the backup for Site B, and vice versa. There are all sorts of simple ways to share the load across your different servers.
Q: What are some misconceptions about how to increase system longevity?
A: These days, there’s a lot of pressure to get end users to buy unlimited I/O tag licensing options. As listeners may already know, most SCADA platforms price their licenses, at least in part, according to the numbers of I/O they connect. But this won’t help them grow indefinity. It simply means they’ll end up paying for more tags than needed. The fact is no computer can run “unlimited tags,” and few end users are planning to continuously grow their systems for years at a time.
This often points to the fact that many common SCADA products make it difficult to update their tag counts or add features. With VTScada, you just get an updated installation key and run the installer again.
Q: What questions should listeners be asking if they want their SCADA to outlive them?
A: What is the typical life expectancy of the software platform being considered? Does this vendor periodically retire versions of their software? How many third-party products are required for basic functionality? How many end-user software license agreements do you need to agree to install the software? How much custom code is required to make it work? What is the strategy for system updates five years or 10 years down the road? How many tags do we need now? Do we need unlimited tags? How difficult is it to add tags and features as we go?
About Chris Little: Chris has been with Trihedral since 2007. In addition to serving VTScada customers in Ontario and Quebec, he serves as Trihedral’s communications expert producing a variety of marketing resources including webinars, articles, press releases, and brochures. His articles have been featured in numerous print and online water/wastewater publications.
Originally published: The ‘100-year SCADA system’ | Control Global