1 September 2002
Will Web services replace HMI?
By Jim Strothman
Partly, perhaps. But not for high data, near-real-time needs.
Low-cost technology to make data available "from the plant floor to the top floor," as the old, overused saying goes, may finally be emerging.
It's coming in the form of Web services, and its promise extends beyond the boardroom to possibly also help manufacturers' sales departments and other business decision makers.
However, Web services technologies are not yet "ready for prime time" by plant floor operations and maintenance personnel, a major human-machine interface (HMI) supplier cautioned. Web-based software simply can't compete with today's HMI systems when it comes to satisfying HMI users' demands for rich, responsive animation, high-data throughput, and close to real-time screen control.
Broadly speaking, a Web service is a URL (browser)-addressable resource that provides data to people or machines wanting it.
Web services are based on widely accepted open standards, such as hypertext transfer protocol, extensible markup language (XML), and simple open access protocol (SOAP). Future versions will also be based on compatible emerging standards being developed by standards groups, such as the universal description, discovery and invocation specification and Web services description language.
Analysts tracking Web services technologies expect HMI vendors such as Siemens, Rockwell Automation, Wonderware, Intellution, U.S. Data, and Citect to roll out additional Web-based products, perhaps as extensions of their HMI systems.
"It would be a natural for them," said Dick Slansky, senior analyst at ARC Advisory Group in Dedham, Mass. "After all, what does HMI do? It collects information, aggregates it, and puts it into a user interface. A Web service would act like a portal to the Internet so that information can be shared."
However, Daryl Walther, a product manager in Rockwell Software's visualization business, cautioned, "Web services does not have real-time response built into it. It won't replace existing visualization systems because Web services is, plain and simple, not fast."
Rockwell offers a Web server extension to its Windows-based RSView32, an integrated, component-based HMI for monitoring and controlling automation machines and processes. Called RSView32 WebServer, the software enables RSView32 users to check access graphic displays and tags via any standard Internet browser.
"If you want to call in from home and get a status update, it's good for remote access—but not for real time and certainly not for control," Walther said.
Microsoft, IBM lead push
Microsoft and IBM, longtime leaders of the global efforts to standardize Web services, are both aggressively pushing software incorporating the technology. Microsoft's .NET (pronounced dot-net) architecture includes a flavor called .NET for Manufacturing.
Last February, Microsoft and IBM were among a broad group of technology leaders who formed the Web Services Interoperability (WS-I) Organization, a cross-industry initiative designed to accelerate developing interoperable Web services across a variety of platforms. Other WS-I founders include Accenture, BEA Systems, Fujitsu, Hewlett-Packard, Intel, Oracle, and SAP.
Since then, a host of other vendors have jumped aboard the WS-I bandwagon, as have some major users, including Daimler/Chrysler AG, Ford Motor Co., and United Airlines.
While Java—particularly J2EE—dominates enterprisewide systems, "Microsoft owns the factory from the server on down," Slansky observed.
"Those who have invested in a Microsoft platform will be more inclined to add .NET," said Sophie Janne Mayo, director of wireless and e-commerce implementation services research for high-tech market research firm IDC in Framingham, Mass. "If they are a Sun Microsystems shop, more than likely they'll stay with that [J2EE] strategy."
HMI experts warn .NET for Manufacturing has weaknesses, however. Microsoft positions Web services' SOAP as .NET's principal remote messaging technology. SOAP's polling strategy may be alright for low-bandwidth requirement markets and for the general use Web. However, it falls short in performance for high-end HMI and real-time data acquisition, they say.
"Users and manufacturers alike are trying to identify what .NET's benefits are, what elements are usable, and what .NET elements are not usable," said ARC's Slansky.
XML and SOAP add complexity and, by definition, don't lend themselves to real time, Walther said.
The Rockwell product manager said one of the company's customers, a West Coast electric generation utility, provides Web extensions to its customers—but strictly for read-only information.
Early adopters mum
Several major manufacturers are known to be testing Web-based systems, probably including Web services, but details are hard to come by. Boeing's Wichita, Kan., commercial airplane plant is reportedly implementing IBM's WebSphere to enable collaborative manufacturing with its supply chain. Honeywell and Siemens are both developing .NET-based systems internally, sources said.
Computer build-to-order pioneer Dell successfully implemented Web-based technologies, including Web services, to fix a supply side problem.
Hewlett-Packard's printer division reportedly uses eRoom, an application enabled for Web services delivery, as an exception management tool for supply chain coordination. When a stock out or other exception is detected, eRoom alerts those charged with managing the exception to "meet" in the eRoom environment.
eRoom Technology said more than 650 companies use its digital workplace software, including Airbus, A. T. Kearney, Aventis Pharmaceutical, Bausch & Lomb, Compaq, EDS, Flextronics, Ford, HP, Pharmacia, Pfizer, Siemens, Solectron, and Sony.
General Motors Corp., which already uses Lotus Notes and the Internet to connect its employees, suppliers, and customers, has reportedly begun pilot Web services tests conducted by its main outsourcer, EDS. By year's end, the effort could enable employees to access and aggregate vast stores of GM data via the company's 130,000-seat Lotus Notes installation.
GM also hopes to use Web services standards to deliver new customer services. Behind this is the fact that any application incorporating Web services standards can discover and connect with any other Web service. GM is said to be testing Microsoft's .NET Web services software, IBM's WebSphere, and Sun Microsystems' J2EE Java software.
Server centric to device centric
According to ARC Insights, written by Slansky, Web-based technology coupled with embedded intelligence at the device level will combine to change next-generation factory architectures from today's server-centric systems to becoming "device centric" systems.
"Only in recent years, with the advent of Web-based technology and advances in embedded intelligence, has information been accessible from low-level devices such as sensors, gauges, motors, drives, and valves," according to the report.
With Windows-based PC systems dominating plant floors below the server level, Slansky said he expects Microsoft's .NET system to amass significant support among manufacturers. However, today "they're having trouble understanding what .NET for Manufacturing is. How does it differ from DNA for Manufacturing and tiered architecture?"
The analyst said discussions with manufacturers led him to believe they really don't understand what's involved enough to move to a .NET environment. "Microsoft is saying it's a major evolution—akin to moving from DOS to Windows. If so, [.NET] will be hard to sell to manufacturers based on Windows. They'll have a lot of code to rewrite."
IDC predicted professional services around Web services–related projects will generate $7.1 billion in the U.S. by 2006, representing a spectacular compound annual growth rate of 116%. IT
Behind the byline
Jim Strothman is associate editor for InTech magazine.