For just the DCS part of that installation, the company had roughly 30 servers that now run on 12 virtual machines. There were about 60 client workstations, and those are now hosted by 10 virtual machines. Using a virtualized private cloud to reduce the number of PCs from 90 to 22 cleared up a lot of floor space, and cut the firm's heat load dramatically.
Besides these benefits, according one of its engineers, the pulp and paper company has "broken the hardware-software link that often drives us into much more expensive repairs and upgrades than should be required. This happens when something like a hard drive fails in a relatively old box we're running as part of a process control system. Then, when we get the new hard drive, we find there are no drivers (or other incompatibilities) available for it on the old box. Next step is looking at a new server that—guess what?—won't run the old application software. And then, you've reached the point where a failed hard drive results in a major hardware and software upgrade. Admittedly, this wouldn't happen if everything in all our systems was up to date—but everything's not up to date."
This example points out a major benefit of virtualization and private clouds, and that's application and hardware platform longevity. With a virtualized private cloud, a hardware failure on a PC simply requires a transfer of the applications running on that PC to another PC in the cloud.
Depending on the cloud configuration, these types of transfers can occur either manually or automatically, and in either case, very quickly, as opposed to what's needed in a traditional installation. For this company, transfers occur automatically, as it uses VMware technology to run mirrored machines with automatic switchovers.
With most every cloud implementation, including those at the pulp and paper company, the availability of a spare virtual application server allows testing of software patches and other upgrades with greatly reduced risk to operations, another reason to move to the cloud.
Many PC-based installations require periodic upgrades for various reasons, such as the upcoming discontinuation of support for the Windows XP operating system. This can be an ideal time to switch from a traditional one PC/one operating system installation to a virtualized private cloud.
"We recently replaced a set of eight stand-alone rack-mount servers that were five years old and due for replacement with two rack-mount host servers designed to run the equivalent of the existing system as virtual machines," reports an automation engineer user at a large water/wastewater utility in Southern California.
The utility uses VMware's ESXi 5.0 software, and Wonderware's Archestra (www.wonderware.com) is the HMI/SCADA system. The following standalone machines were converted to virtual machines in a private cloud, and are running fully redundant with the ability to have one of the two host machines fail with no loss of SCADA functional Archestra System Platform object servers, Wonderware historian, domain controller, terminal server and I/O servers (communications to PLCs). Besides greater reliability, this private cloud installation gives users the ability to add virtual machines to host servers to expand SCADA system capacity.
The downside of the private clouds is that they require significant internal expertise. Despite this, strong growth is expected to continue.
How Far Can the Cloud Go?
Private clouds are already in widespread use in the process industries, and remote access and asset management SaaS solutions should continue rapid growth. Users trust private clouds in critical real-time control applications because they're an onsite solution contained within a particular facility. At least some users are comfortable using cloud-based remote access and asset management, probably because these services don't directly affect real-time control. It seems that this will be a pattern going forward, as process industry firms will limit cloud use in real-time control to private clouds, and will only trust SaaS providers to the extent that they don't directly affect real-time control.
"At this point, our company doesn't use clouds in our server level and other process automation applications, primarily because we view it as too risky due to a lack of cloud standards and insufficient knowledge," cautions Rick Hakimioun, a senior instrument/electrical and control systems engineer with Paramount Petroleum.
"Process automation professionals must go through a paradigm shift to start taking advantage of cloud innovations, and I see it happening in few years. Of course, we must first fully understand how it works, and we will need to have the control systems suppliers' blessings of the cloud before jumping on the bandwagon," observes Hakimioun.
"Security and a lack of standards are the biggest concerns. IEEE, ANSI, ISA and other non-profit organizations will need to be the forerunners on putting together the security and interoperability standards for process industry cloud-based applications, not vendors like Google and Microsoft," he adds.
Automation vendors will have to be fully on board also, as Hakimioun and other end users tend to trust their reputable automation suppliers over others when it comes to maintaining a secure, cloud-based system.
A system integrator seconds Hakimioun's opinions. "Private clouds are popular, but public cloud services such as Amazon's EC2 are less likely to be used for two reasons. Control networks are usually segregated, and do not have access to the Internet, and manufacturing customers like to have their servers inside the plant, minimizing points of failure," observes Chuck Toth, MSEE, a consultant with Maverick Technologies.
Other cloud caveats include dependence on the continued existence of the cloud services provider, and dependence on reliable and high-speed Internet connections. If the cloud services provider were to go out of business, then a process company's entire cloud-based remote access or asset management system would fail completely and instantly. Although the customers of cloud-based storage provider Nirvanix didn't lose all their data instantly, they were only given days to scramble to find a new supplier when the firm recently failed.
Perhaps these types of failures and wariness of others are why many end users want to see their main automation system vendors as providers of cloud-based services.
And no matter who provides the cloud service, all public cloud operations, unlike private clouds, depend on the reliable operation of high-speed Internet and other external communication systems.
The cloud is here to stay in process automation, and its use will spread in the form of virtualized private clouds, and for remote access and asset management applications. Further penetration of public cloud-based applications will require increased participation of automation system suppliers and standards organizations.