Computers, centralized information management systems, building automation systems, communications networks and system interoperability — these and other technologies have given facility executives unprecedented access to information. Properly used, this information can lead to better management and more efficient facility operation. These improvements are significant in and of themselves, but they are having a cumulative effect that is producing a major change in the way facility executives view their facilities.
Increasingly, buildings and their supporting systems and components are no longer viewed as simply passive elements to be acted upon. Instead, they are increasingly seen as being active components in the management process, serving as a source of information needed to make day-to-day decisions. The result is an even higher level of demand for information from building systems.
While many developments in building automation have helped improve access to information, they have not provided the framework that is required for easy information exchange. In many cases, managers could retrieve information from one system but not easily provide it to a separate system. Even with interoperability, facility executives found numerous roadblocks halting easy information exchange.
Enter XML. XML, which stands for eXtensible Markup Language, is a software standard widely used in the IT community for data exchange. It is an open and flexible standard for storing, publishing, and exchanging information. It allows users to transmit any kind of information over an existing IT infrastructure, such as the Internet or a company’s intranet, regardless of the operating protocol in use by either the data requester or the data provider. It enables business information to become independent of proprietary data formats and applications. This means that users of XML can share data across different software applications and operating systems without having to upgrade or replace those applications.
XML was developed in 1998 by the World Wide Web Consortium (W3C), and has gained widespread acceptance in the IT community, including universities, research labs and a range of industries. XML offers the promise of being to data exchange what HTML has been to data display on Web pages. While HTML standardized the way different kinds of information should look across multiple platforms, it did not provide the necessary structure for organizing and exchanging data. XML provides users that organization and structure.
One of the most common fears when any new software package or standard is introduced is that the existing IT systems will have to be changed to meet the needs of the new standard.
That is not the case with XML. Because XML is a standard for Web communication, all existing applications can remain unchanged. XML tools will have to be constructed to allow data extraction from those applications, but the applications will be able to continue to run as they have.
The language and terms associated with XML can be confusing, even to those who regularly work with building automation systems. Therefore, before looking at the potential impact that XML will have on facility applications, it is beneficial to look at XML basics and how it is being used today in other fields.
XML is a markup language for documents that contain structured information. It is an outgrowth of Standard Generalized Markup Language (SGML). It has become widely used for delivering information over the Internet, particularly between systems using different platforms.
XML, like HTML, uses a series of “tags” to describe the content of the data. A tag is a text command inserted into a document or data series. Tags appear at the start and the end of each data segment. In HTML, the tags focus on how the information is to be formatted and presented. In XML, the tags describe the structure and the meaning of the data.
One of the features that has been built into the XML standard is that new tags can be defined as needed as data requirements change, giving vendors and users flexibility and allowing the standard to develop as needs arise.
When hardware manufacturers and software suppliers talk about XML, they often use the term SOAP. SOAP stands for Simple Open Access Protocol. It is the protocol used to encode the information transmitted over an Internet or intranet backbone that allows data to be transferred between different systems, without having to know the details of how those different systems operate.
XML is used to tag the bits of data that are sent between the applications; SOAP is what transfers the data.
The entire system that links the various applications together over an Internet or intranet backbone is what is known as Web services. Web services integrate applications by making use of open standards such as XML and SOAP that eliminate the need to program custom interfaces. With Web services, differences in operating systems and programming language no longer are an issue.
One of the most significant benefits of XML is that it allows facility executives to establish and build on a standard that will allow the exchanging and storing of information between and among systems in a format that is independent of any one manufacturer. Choices are no longer limited by the existing systems./p>
XML is also extensible, meaning that as needs change, the standard can be modified by individuals and organizations to meet the needs of specific applications. As those needs develop in the future, the standard will allow users to continue to modify it.
Using XML also will allow better management of the data generated throughout the facility. Data management will no longer be driven by the vendor chosen for a particular project. Instead, with a standards-based approach, data management will be driven by needs.
It must be understood that XML is a specification that is standards-based and does not belong to any one company. With no single company owning or promoting it, there always is a risk that something better might be developed in the future that makes XML obsolete. That risk is particularly low in that there is nothing on the horizon today that would serve as a replacement for the standard.
One of the most significant challenges facing facility executives today is effectively using the wide range of information made available by various building automation systems, maintenance management, financial management and asset management systems. XML holds the promise that building automation systems that use XML will allow seamless communications between those systems and with other IT systems, such as accounting and asset management.
How close are we? Several groups are working to integrate XML standards into building products for data exchange. Both BACnet and LonMark are working on ways to incorporate XML into systems that comply with their standards.
Although both of these standards already address the issue of exchanging data across a network, applying XML will address other boundaries that exist for sharing data across platforms containing information that will need to be shared in a fully integrated operation. XML will not replace BACnet or LonMark but rather will enhance their effectiveness.
The Continental Automated Building Association (CABA) also launched an effort to develop standardized ways of using XML for data exchange in building automation systems. With members from the security, building automation, HVAC and IT fields, CABA began developing guidelines for implementing various attributes of XML in building automation systems. The objective of the Open Building Information (oBIX) guideline is to develop a standardized way of implementing and managing intelligent buildings.
Applying XML in a facilities environment will present challenges to managers and IT people alike. Issues such as security, traversing firewalls, support and compatibility with business applications must be worked out for each. But the potential is there with XML. Organizations that are willing to work through the challenges will find that they have greatly expanded their access to building data. And that data can then be added to other management data that they have come to rely on, resulting in even more powerful management tools.
James Piper is a writer and consultant who has more than 25 years of experience in facilities and management. He is a contributing editor to Building Operating Management.
Developments in XML and Web services promise to make it easier to integrate building automation and business systems to create enterprise services for facility executives.
The Continental Automated Buildings Association (CABA) recently transferred governance of Open Building Information Exchange (oBIX) to a technical committee at the Organization for the Advancement of Structured Information Standards (OASIS). “We are pleased to have initiated and nurtured the formative stages of oBIX,” says Ron Zimmer, CABA president and chief executive officer. “We expect that the shift to OASIS will accommodate the creation of a complete Web services specification devised specifically for the operation of commercial buildings.”
Meanwhile, the XML Working Group of BACnet is working on a draft specification. “The news is we are working very hard and expect to have results very soon,” says H. Michael Newman, manager of the utilities department computer section for Cornell University, past chairman of BACnet and convener of the XML Working Group. “It won’t be much longer before we have real specifications for using Web services regardless of the underlying structure.”
LonMark International also has eXtensible Markup Language (XML) capabilities, as do the major proprietary controls systems.
The objective of oBIX and BACnet’s Web services is to have a common, standardized, secure way to manage intelligent buildings with greater interoperability. Web services is a set of technologies that allows machine-to-machine communications using two IT standards called XML and Simple Object Access Protocol (SOAP).
The design objectives for oBIX is to work through OASIS to create standard XML and Web services guidelines that will facilitate the exchange of information between intelligent buildings, enterprise applications and building systems. Based on standards widely used in the IT industry, oBIX is intended to improve operational effectiveness, giving facility executives increased knowledge and control of their properties.
“It’s important to note that we are not developing a control system, but rather an interface to controls systems,” explains Toby Considine, manager of technology services for facilities operations at the University of North Carolina and new oBIX chair. “Working with OASIS is a new way of working, but it’s already clear that we are getting significant benefits from OASIS.”
Jeremy Roberts of LonMark International explains the XML developments by comparing the facility executive to the operator of a car. “XML is a way to get information from point A to point B,” Roberts says. “When you look at the dashboard in your car, you want to know the miles per hour the car is traveling. You don’t care what the protocol for the engine is or how miles-per-hour is transmitted to the dashboard.”
The design objectives for the BACnet/XML and Web services specification will support remote “read,” “write” and “find information.” The specification will be compatible with industry standard IT security mechanisms and will support the connection of systems through network address translation devices and firewalls.
— Rita Tatum, contributing editor