Building Operating Management

Interoperability Scorecard

The promise of interoperability has raised expectations among facility executives; here’s how today’s systems are delivering

By Benjamin Lund   Building Automation

For years, facility executives have been reading and hearing about interoperability. Interoperability has been promoted as the road to managing operations more efficiently and effectively. Manufacturers have promoted the systems as here and now and simple to install. Experts have preached the wonders of interoperability.

But while some users have achieved tremendous successes in installing and operating interoperable systems, others have not been so fortunate, with subsystems and components that may or may not talk to each other.

Why the discrepancy between what is being promoted and what is actually being achieved? Part of the difference can be attributed to over-enthusiastic salespeople convincing under-informed facility executives of capabilities that simply are not yet achievable. While tremendous strides have been made in interoperable systems, they are not what one would call “plug-and-play.” One cannot simply plug a new controller into a system the same way that VCR is plugged into a TV and expect everything to operate properly. While the industry is working towards plug-and-play, it is not there yet.

That does not mean that interoperability can’t be achieved, nor does it mean that interoperability currently is so difficult to implement that facility executives would be better off waiting. Interoperability is here and is being used successfully. While implementation may not be as easy as some have been led to believe, most of those who have been through the process say they would do it again.

An underlying issue is lack of understanding among many facility executives as to what interoperability is and what it can do. An interoperable system is one that combines a wide range of building automation functions — functions that traditionally have been performed by independent systems — into a single system that provides common communication, control and data capabilities throughout the system. Typical functions that are included in an interoperable system are HVAC, lighting, energy management, work management, cost accounting, security, fire safety and industrial control.

This concept of integrating all building automation system functions into a single, facility-wide system sounds relatively simple in theory, but it has proven to be a challenge in reality. Early attempts at interoperability were focused around proprietary systems that manufacturers designed to include a wide range of building automation functions. But while these systems did achieve a certain level of interoperability, they did not provide all of the benefits of today’s interoperable systems.

The Real Benefits of Interoperability

In spite of the potential rough road to achieving interoperability, facility executives in particular and the industry in general are steadily moving in that direction simply because of the wide benefits interoperability offers. One of the most significant of these is the single seat interface. With independent building automation systems, operators are forced to work with a number of separate systems, each with its own interface. Since each system was developed around proprietary hardware and software, there are significant differences in how information is entered, accessed and displayed in each of the systems. Operators and technicians must learn the syntax and operational rules and aspects of each system in order to use them. With multiple systems in a facility, simply learning how to use each one can be a challenging and time-consuming task.

Interoperability eliminates the need for multiple, independent systems. With a single interface to all automation functions in the facility, operators and technicians need learn only one set of rules and commands in order to operate and maintain the entire system. No more confusion and lost time while operators struggle to remember obscure commands.

Interoperability also improves the operating efficiency of the facility management department. Users of independent systems frequently find that the data they need to use in one system is available only in another, separate system. Since those systems cannot communicate with each other, data from the first system has to be printed and then manually entered into the second one, wasting time and greatly increasing the chance for errors.

Interoperability, with its ability to make data generated anywhere in the system available to any other part of the system, eliminates data transfer tasks, improving efficiency and accuracy.

Vendor independence is another often-cited benefit of interoperability. With independent, proprietary systems, owners were locked into one system manufacturer for all future expansions and upgrades. This lack of competition helped keep system prices high while limiting innovation. Equally important, system owners were at the mercy of system manufacturers. If the manufacturer went out of business or chose to no longer support that particular model of building automation system, owners were stuck with orphaned systems. Their only options at that point were to upgrade the system to one that the manufacturer would support or to replace the entire system.

Vendor independence reduces the possibility of installing a system that will become orphaned at some point in the future. Vendor independence also helps to preserve competitive bidding on future system upgrades and expansions, while giving owners options when it comes to system features and capabilities.

Interoperability also enhances the capabilities of building automation systems. It is a case of the whole being greater than the sum of the parts. With the seamless access to data, facility executives find that they have better access to information than with independent systems, allowing them to perform tasks that were previously difficult or impossible. Enhanced control strategies, complex energy management capabilities, maintenance activities and schedules tied to system performance — all are examples of tasks that can be performed in an interoperable system.

Facility executives have several options when it comes to implementing interoperability. With the move away from proprietary systems to open standards, a number of different standards have currently emerged as suitable methods for achieving interoperability. The most common systems being used today include BACnet, LonTalk, ModBus and OPC. Each of the standards offers its own particular advantages and disadvantages, so facility executives can select the one that is best suited to their particular needs.

Interoperability Today

While great advances have been made in interoperability, one must remember that this is an evolving technology. Early attempts at interoperability were based on proprietary systems from a single manufacturer. Today, interoperable systems are based on open system protocols. And while developing and implementing these protocols are important steps in the evolution of interoperable systems, they are not sufficient by themselves. One must remember that when operating in a multivendor, multifunction environment, overall system performance will be no greater than the weakest link in the system. There remain today a number of weak links.

One of the most significant weak links is the lack of plug-and-play capabilities. While standard protocols have led to interoperability at the system level, they have not been so successful at the controller level. Standard protocols dictate how devices will communicate over an interoperable system, but they do not dictate how that particular device will operate. As a result, different manufacturers use different approaches at the device level, including different programming methods. The result is that owners cannot simply replace a controller from one manufacturer with a controller from a different manufacturer, even though that replacement controller complies with protocol standards.

Many controllers use proprietary software in their operation. Differences in how those controllers are programmed prevent a simple plug-in replacement. These differences can even prevent owners from replacing a controller with a different model controller even if it is from the same manufacturer. This use of proprietary software at the controller level also means that owners have not gained complete independence from vendors. To diagnose, program or update those controllers, system owners will have to purchase proprietary tools from the manufacturer. Until this issue of interoperability at the controller level is addressed, the systems will not achieve true plug-and-play operation.

Another weak link in interoperable systems today is a result of the way in which some building systems are designed and built by their manufacturer. Many manufacturers have designed their systems to run under local control, with some limited capabilities for remote monitoring and control. If those systems are to live up to the full capability of an interoperable system, then system operators must be able to monitor and control all remote system parameters from a central point. To accomplish this, equipment manufacturers will have to change their design philosophy to take into consideration interoperability.

Finally, because interoperability is new and is rapidly evolving, it is difficult to find someone with expertise and experience in designing and specifying interoperable systems. This lack of expertise has resulted in many owners relying on the guide specifications provided by specific vendors, rather than specifications based around their particular needs. As a result, they may end up with an interoperable system, but a system that is based solely around one manufacturer’s products. Even worse, they could end up with a system that does not meet their needs. As more systems are installed and more experience is gained with their design and operation, the availability of expertise will improve.

Getting There from Here

The current state of interoperability should not be a deterrent for a facility looking to install a new or upgrade their existing building automation system. Rather, it should forewarn facility executives as to the need to do one’s homework before jumping in.

  • Start by defining just what it is you expect to accomplish through interoperability. Look closely at your existing building automation systems to identify those that would benefit from being integrated. For new facilities, look at the functions that will be performed in those facilities to determine areas that would benefit from interoperability.
  • Don’t simply select the first protocol that you see. Each of today’s protocols has its own strengths and weaknesses. Protocols must be selected on the basis of the facility’s needs and the ability of that protocol to meet those needs. If in-house expertise is not available, seek help from a qualified, independent firm.
  • Involve your facility’s information technology department. In almost all cases, the building automation system will be using an existing network within the facility. Since that network is generally under the control of the information technology department, involve them early in the evaluation of protocol options to prevent incompatibility issues down the road.
  • Develop specifications that are sufficiently detailed to support the project.
  • Identify the standard protocol to be followed.
  • Define who is responsible for system integration when equipment from different suppliers is to be installed.
  • Define documentation requirements.
  • Specify a thorough commissioning process that clearly defines criteria that must be met before the project is accepted.
  • Thoroughly research the companies that are offering to install the system. What is their experience with interoperability? How many systems have they installed, and how interoperable are those systems? How did they achieve interoperability? How do the owners of those systems feel about their installations?

Don’t Wait

Interoperability is ready for prime time. Interoperability is here and is being used successfully today. Any facility executive contemplating a building automation project, particularly in new construction or a major building renovation project, should take a serious look at interoperable systems, recognizing that interoperability is still evolving. To help in wading through the wealth of this information, facility executives must thoroughly educate themselves about what interoperability is and where it stands today. Thousands of facilities are currently using interoperable systems. It is only a matter of time until the proprietary building automation system is a thing of the past.

James Piper, PE, PhD, is a consultant and writer with more than 25 years of experience in the facilities field.

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  posted on 1/1/2002   Article Use Policy

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