Object Architectures in an Increasingly Services-Oriented World

“Another example is integration of production management and business systems. Usually this includes business systems sending production schedules to automation systems, and the automation systems sending back production results. The ISA-95 standard and B2MML (Business To Manufacturing Markup Language) is used in many companies to implement this type of interface.”

“As large, multisite companies move to SOAs at the IT level, it will become critical for them to integrate their manufacturing systems into the architecture. IT infrastructure companies have different offerings in this area, but all are based upon web services and delivering robust infrastructures. At Yokogawa, our intention is for our automation systems to cleanly interface with our customers’ preferred IT infrastructure environment. To do this we are working with multiple IT suppliers and utilizing standards-based web services as our preferred interfaces to exchange data with other systems.”

Chevron Richmond Refinery. Photo courtesy of Chevron Refining

“Yokogawa is also a strong supporter of the OpenO&M standards. OpenO&M is an umbrella group of different standards (ISA95, WBF, MIMOSA, Open Applications Group and the OPC Foundation). Each individual group is working to develop standards for integrating manufacturing systems using XML and web services. Yokogawa believes that standards-based interfaces are required to provide the lowest possible total cost of ownership for our customers. Standards-based interfaces will enable manufacturers to integrate more easily different manufacturers’ systems as each will be able to “speak” a standards language and avoid the many-to-many point interfaces that using proprietary formats would require,” said Yokogawa’s Emerson.

According to Emerson’s Peterson, “Emerson promotes the platform independence provided by an SOA built on web services as the direction the industry is taking, and we’re continuing to develop web services that provide meaningful information and integration. These services allow customers to integrate enterprise-level applications with the process system more easily and enable greater productivity by tying process and business information together at all levels of the organization. This can push decision making down the management chain, enabling quicker reactions to changes in the market.

“Web services are, by their very nature, self-describing. This allows for easy integration without prior knowledge or distribution of precompiled code. Application developers simply need to know the name of the service and its location on the network to begin immediate integration. Currently vendors are beginning to offer their own custom set of services or custom applications that integrate proprietary services to address specific customer needs. These are very specialized solutions that come at a higher cost of custom development,” said Peterson.

Hal Allen, SCADA specialist at Santee Cooper Power. Photo by Jim Huff, courtesy of Santee Cooper Power

According to Rockwell’s Briant, “FactoryTalk Services is currently based on DCOM, but we’re moving the platform more toward next-generation technology by exposing objects as web services. This can provide a lot of value for businesses.

“Big benefits for customers include the ability to get the right information, providing users with access to the things they need,” said Briant. “It certainly also reduces engineering costs because you don’t have to duplicate information or create users twice or three times. You can use some of the objects that we support in our services and then link them to a Windows object of a similar type for Windows-based security. From an operations and maintenance perspective, as people come and go from a plant or organization, you can add users, take away users and do that at the IT level without disturbing the plant-level maintenance support people. Some of the appeal is that IT people can understand what’s happening at the automation level.

“SOA will absolutely play an important role in automation. I think the concept of interoperability, or what the IT people would call application integration, is key. From an IT perspective, questions like ‘How do I integrate applications across workflows?’ often come up. This is an expensive item that costs money to knit together applications within a company or across vendor boundaries,” said Briant.

Santee Cooper Power substation. Photo courtesy of Santee Cooper Power

“Business systems want to have more information about and a role in driving production. More information will be required to pass between the production and business systems than was possible to package up and serve out as a single tag, as was the case with OPC (DA). Part of that will be knitting in the customer, the user, the operator, the receiver, the shipper, all the people that touch that manufacturing activity, and making sure that they package all that up. The goals and objectives of OPC UA fit that model of how we as a community of industrial automation suppliers can expose things at a richer level to be able to answer questions, such as can we do it securely? Can we add users and groups?  Can we add a security model that guarantees that those requesting information are authorized to do so? These kinds of questions are starting to come to the forefront,” said Briant.