To complement this month’s scada issue of SA Instrumentation and Control we invited a group of vendors, SIs and end-users to participate in a round-table discussion around these questions.
Our goal was to provide readers with an informed and multifaceted understanding of whether the design decisions made by scada vendors are significant in terms of the ease of engineering, maintenance and use displayed by delivered systems.
Of course, chairing a meeting filled with experts who are passionate about scada is akin to herding the proverbial cats, so readers will need to make up their own minds on whether we achieved this goal.
Runtime environment
Platforms, .NET and Java
AA: Thanks very much for making time to join us today. You have had some time to think about the topic, so let us get the ball rolling with an example. When I talk about fundamental decisions I am not talking about whether an object on a scada screen is coloured red or black, whether it appears in a big font or a small font. I am talking about the nitty gritty fundamental engineering decisions that happen prior to the development of a product or a module.
So what about runtime environment? Pure Java or Windows? And if Windows, then Windows Forms or Web Forms built on ASP.NET libraries? Which is the way to go? How do these decisions, or indeed do these decisions impact on end users?
ML: In terms of the technologies, .NET, C++, Java and all the rest, I think .NET lends itself ideally to the visualisation side of things whether you are transporting across the Web or whether it is on a local PC or LAN. At the server level, our opinion at Adroit is that .NET is still too clumsy to meet the real-time speed requirements. The choice does not impact the customer, he wants the functionality.
NvdW: At Bytes we definitely feel that building on the Microsoft .NET platform has positive spin-offs for clients. There are large numbers of .NET capable programmers in the world and even in South Africa. That is important for end-users because it means that applications are more supportable.
PdSG: Yokogawa has a different point of view. Its FastTools scada application has been developed as a true Web-based scada system. Written in Java, it is platform independent, giving the client freedom of choice of operating system, and not limiting them to Microsoft platforms.
By using Web plus Java technology the end user only needs a Web browser and that can also be platform independent. The user experience is very similar to Internet banking, where you open a session at the Web server and that technology is brought forward to the user on the display side.
Because Yokogawa’s zero deployment solution is not tied into any particular operating system or browser its Java-based solution will be far more likely to postpone obsolescence than solutions based on a specific operating system.
There are also other benefits in adopting Web-based technology: the application can be deployed to all levels within an organisation; and corporate IT can easily manage the entire security of the scada application. We think that these are important considerations for end users.
AA: Sean, what is Rockwell’s take on this from a vendor perspective?
SH: I think you have to have a look at what the world is doing. Rockwell is Microsoft oriented and that is never going to change.
CM: From Quad’s perspective as an SI, our requirement is to please our end-user and make sure that the components integrate into a seamless system. Where vendors supply us technologies that are not easy to integrate, it makes our life difficult. So when vendors consider technologies that they are going to adopt it is important that they ensure that what they are going to be rolling out is easy to integrate. .NET technologies and plug-ins help in this regard.
QM: As far as .NET and platform are concerned Schneider Electric follows the lead of Microsoft and works very closely with them. We know what new technologies are coming out and we always try to take advantage of the new features that are developed. There are a lot of skills for Microsoft out there.
HK: Microsoft to a certain extent has also become a standard and Siemens bases its technology on theirs. It is ubiquitous and know-how is available.
AA: But do you think that those technological decisions that you make, at the development level, do or do not impact on the end-user?
HK: I am not so sure whether that is of importance to the end client, because the question comes down to the client saying, “I use a particular technology, can you hook up with it?” And the only answer from a vendor perspective can be “Yes”. If you are stupid enough not to follow that then you keep yourself out of the market.
EvW: I want to agree with that. We do not supply hardware so our bread and butter come from being able to connect to everything. We have to be able to walk into a plant and communicate with the existing systems. Microsoft technologies provide us with that openness.
Whatever technology comes out from Microsoft we try to adopt; for instance, we are in the process of releasing our new Web client which is Silverlight based.
In items of integration, it is important to allow the end-user to decide what he wants to use, what he wants to be able to implement on this plant and what technologies he wants to leverage. There is a very big space for visualising scada, MES and other layers via the Web, but there must be some services that are outside the Web environment: especially when we are talking high speed services, aggregation, historians, and the like.
Virtualisation
SH: A question to the other vendors. In IT architecture there is a strong movement to virtualisation; virtual PCs and VMware. We have had requests for it, and it seems like a good fit for some of the system architectures that Quintin spoke about. You could put two decent machines down in a redundant configuration and load virtual scada machines for a bunch of subunit scadas at a lower cost from a hardware perspective and still have the redundant network but you are running in a virtual environment. What do the other vendors feel about this technology?
EvW: There are a lot of people that want to do that. I do not know how many are actually running it but we have got a couple of customers trying to implement it. Just as an aside we asked our customers, “What do you want?” And they all came back and said, VMware ESX that was about three years ago. And in the last year and a half we went back to them, and asked, “What do you want?” And they all said Hyper-V. So we built in all the support for VMware ESX and now we have got it and they are running out support for Hyper-V probably in the next couple of months. So it shows you, within a year and a half, it has swung from one side completely to the other side.
PP: VMware must be supported by the vendors, agreed. But should end users put it on site? I’ve had lots of bad experience with it, so no, I would not develop or design a system for an end user that uses VMware to try and save a PC. Rather put a second PC down. That’s it.
JF: I suppose that depends if you are going for the cheap VM option, or if you are going for the full blown ESX server option where you have multiple servers. They actually provide much more enhanced redundancy than you would have with only two servers. But the problem is most plants would not be able to support a system like that unless they had an IT department looking after it.
Lifecycle matters
AA: Are there vendor technology decisions that impact on system longevity and lifecycle?
JV: This round-table discussion is delving deeper than Eskom normally goes as an end user. We very much focus on the functional side of what we want from a product and tend to rely on the vendor to provide a product that best meets our functional requirement. We try to avoid getting into the prescriptive side of saying it must be this or it must be that. I think historically we found if we are too prescriptive we can lose out on potential benefits that come from alternative solutions. I think our biggest focus at the moment relates to product lifecycles – especially in our power station environment where we are talking of a 20-year plus life span.
AK: I second what John says.
AA: Browser-based delivery of scada views, where the application and data management are server-side and visualisation is client-side through a browser, must surely improve maintainability and system longevity?
JV: In a big organisation like ours when we want to employ a product to which perhaps 10 000 people will have access, if purchase price is going to be licence-based, then licence cost is a factor that you have to take into account in your evaluation as compared to a solution that is just accessed via an open browser. But I do not think we have really considered the benefits of browser-based delivery from a system maintenance consideration.
QM: In terms of this 20-year lifecycle perspective, I would say from my experience the PLC or hardware world can definitely meet this requirement, but to take advantage of the information and the benefits of emerging technologies you cannot expect to run a scada or MES for 20 years without changing it.
ML: John, when you talk about your 20-year horizon are you saying that the operating systems and technologies must last there for 20 years or are you saying that there must be a road map for 20 years?
JV: In practical terms we do not have the opportunity to replace the actual system that often. We might need to have a migration strategy in place to keep up with IT developments. This off-the-shelf technology that vendors promote causes us problems because it does not have a very long life. But the important point is that we do not want to lose the intellectual capital that we build into the applications.
As a technology consumer we do battle in that when we do an evaluation and we say to a vendor, “What is your lifecycle policy?” Very few of them can tell you more than one or two years ahead which direction they think they are going. They will tell you that they are waiting to see what Microsoft is going to do. So to a certain extent we look a lot at historical performance by the vendor. Vendor ‘A’ has a product that we can see he has supported for the last 10 years. Vendor ‘B’ comes up with a completely new and incompatible product every three years. They will be evaluated differently.
AA: So it is reputational?
JV: Well, it is a bit like when you want to prove that something is safe. You look at the hours of safe operation or in-service operation as a basis for making that judgement. It is the same with the control system. They often say the power industry is very conservative; it wants the latest technology that’s been proven for 10 years.
PdSG: A project like Medupi is going to take seven years to build and you are looking for a system life of 20 years. The control system I/O will offer this, but control systems dependent on present Microsoft operating systems will be outdated or obsolete by the time the construction phase is complete. This is why Yokogawa has put so much effort into platform independence.
JV: Using systems that incorporate commercial IT off-the-shelf operating systems we are faced with a typical IT lifecycle which means that every three years or so we have got to replace all the servers. It is something that the control systems industry needs to revisit.
We have to ask for capital to spend money on a C&I project that we only put in five years ago, but the one that was put in 30 years ago is still working and we are not asking for any money for that because it is still operational and maintainable. Management says, “Why do you want this new technology?” So I think there is a lot to be said for scada, MES whatever you want to put it but do not lose sight of the commercial goal of that investment: it is to run the plant and with the least total cost of ownership. There is a lot of technology out there which when we come to evaluating is not seen necessarily as beneficial.
Last words
NvdW: Different technologies will benefit different projects in different ways. SIs have the responsibility to advise their clients so that they understand which technologies will benefit them and why. Thereafter the SIs job is to deliver the best, most reliable system that will satisfy the needs of the client.
AK: In using technology to improve operations, it must make business sense for the end user. Vendors need to help end users understand how their new technologies will provide business value so that project champions can answer the question, “Why do you want to change stuff that is working?” For investment funds to be released there must be a positive business implication.
SH: A vendor does not make a decision about a technology without input from its end users. It will be end users who determine which new technologies; Windows Communication Foundation, Windows Presentation Foundation, Silverlight and others will become part of our core technology.
JV: As an end user, we are more focused on functionality rather than technology. Product evaluation is more about whether the product can meet the functional requirements than how the system is put together and what is inside it.
EvW: I think if we look back at this conversation five years down the line and read that any vendor or end-user even considered not using Windows Communication Foundation technology, we would have a good laugh. It would not be clever to ignore these technologies going forward.
QM: Schneider recently implemented Windows Workflow Foundation components in its MIS environment. This is very new technology. As we identify requirements we are incorporating workflow components that a user can configure. Users cannot just go wild and build their own workflows yet, but that is the direction we are heading in.
HK: We have more vendors in this room that can design a fantastic plant for Eskom with all the functionality John has spoken of, but when you put a bid in, it is not his decision. At the end of the day it is a commercial decision. As vendors we have to look at how we can minimise the cost of scalability. We have to propose very cost-effective solutions that offer high availability and ease of maintenance. That is what it comes down to.
ML: There has to come a point where you have to make a cut clean from legacy technology.
PdSG: If the scada fails the plant must still be able to stop in an orderly fashion. We have to educate end users so that they understand that scada systems are first and foremost ‘Supervisory’. Architectural levels are a key factor in system design.
JF: The IT industry has durable standard communications interfaces like ADO and ODBC. I can upgrade my reporting system, and it is still going to talk to the database through those standard interfaces and that is how it should be. When vendors choose custom interfaces between their scada, MES and historian components I have to upgrade all the different parts and that results in a plant shutdown. So my vision would be for vendors to move away from these proprietary interfaces and standardise.
CM: On the bigger projects the procurement officers look at the bottom line, that is it. There is no consideration given to what they plan in five years’ time, can they scale it, what is it going to cost to put another 10 servers onto the system when they build a plant next door. They do not look at that.
PP: I would not develop or design a system for an end-user that uses VMware to try and save a PC. Rather put a second PC down.
AA: Each of you as participants of this round-table have years of experience in the application of control systems and scada. Sharing your knowledge openly like this provides huge benefit to readers and the southern African control industry. I am sure that we will all benefit through creating more informed end-users. Thank you.
For the complete article, which also covers round-table discussion on:
* System architecture.
* The Purdue hierarchy
* Upgrade paths and change.
* Customer wants and needs.
please visit www.instrumentation.co.za/papers/C13883.pdfI
About the author
Andrew Ashton has electrical, mechanical and business qualifications and has been active in automation and process control since the early 1980s. Since 1991 he has headed up a company that has developed formulation management systems for the food, pharmaceutical and chemical manufacturing industries and manufacturing solutions involving the integration of various communication technologies and databases. Developed systems address issues around traceability, systems integration, manufacturing efficiency and effectiveness. Andrew is a contributing editor for S A Instrumentation and Control.
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