Modeling Building Automation and Control Systems Jim Sinopoli, Managing Principal Smart Buildings, LLC 2013 Many building owners and facility managers lack good documentation for their automation control systems. Documentation has value; lack of system documentation can cost an organization and will increase risk. Lack of documentation means troubleshooting and work orders take longer, are more expensive and it extends the time it takes to resolve issues for tenants or occupants. It also may mean preventative maintenance isn t done because you don t know what the PM schedule is, possibly shortening the life of the equipment. Or it may mean that facility personnel really do know a lot about their systems but if they move to another organization or company or retire, all that knowledge or system documentation leaves with them. This lack of documentation for automation and control systems is caused by inadequate organization and planning in the handoff from construction to building operations and the fact that much of the documentation is in a paper format. Help is on its way. The buildingsmart alliance with the input of the US Army Corps of Engineers has developed and proposed a data structure for representing information related to automation and controls. It falls under a large umbrella called Building Information Modeling or BIM. BIM If you ve had any involvement in new building design and construction you re probably familiar with BIM. You may be aware or exposed to the 3-D modeling of a building and its components and understand the value it can provide in avoiding potential collisions between the designs created by different engineers. Likewise, the usefulness this modeling can provide to contractors in fabricating building systems and components. Major designers and construction companies have embraced BIM and rightfully so; it can reduce change orders, assist in maintaining schedules and generally produce better buildings. The larger picture and the utilization of BIM should be an approach of a life-cycle asset management tool. Such a tool is used increating and acquiring data during design and construction which is then delivered to facility management. It s the building operations that will be 85 to 95 percent of a building s lifecycle. 1
To facilitate the exchange of information from design and construction to building operation, a standard called Construction Operations Building Information Exchange (COBie) was developed by a laboratory of the US Army Corps of Engineers. COBie is a format of data for building assets. It s associated with BIM, but doesn t involve spatial modeling. It is part of the National Building Information Model. COBie may include data such as preventative maintenance schedules, model numbers, warranty information, product data sheets, and everything needed to operate and maintain the particular asset. Industry Foundation Class (IFC) The modeling of automation systems involves the development of a specific IFC for automation and control systems. An IFC is an open and neutral data model that describes building and construction industry data to facilitate interoperability of the data between designers, contractors and facility management. The IFC model specification is registered by the International Organization for Standardization (ISO) and is an official International Standard (ISO 16739:2013). The effort is referred to as Building Automation Modeling Information Exchange or BAMie. The proposed IFC for the Buildings Controls Domain has core entities to represent automation and control systems. During the design phase, when different design elements are being determined, the data exchange between automation and control systems can be coordinated with other design elements. The proposed domain models for automation systems are controllers, sensors, actuators, alarms and instruments, and control elements that have integrated panels and indicators. The model definitions are organized into addresses, configurations, connections, performance and components and types. 2
1. Connections - The model definition of connections has logical and physical connections. The IfcRelationship entity can then model the connections. Inputs and outputs for devices such as controllers, actuators, thermostats and sensors can be mapped. 2. Components and Types Initially design components may be generic but at some stage of a project specific product data is needed and a product template can be used to organize the data. In this case an IfcType Object entity may be used to acquire product specifications and IfcDocument References can used to provide links to installation and O&M manuals. 2013 3. Addresses This model definition provides an addressing format for specific data points. It also seems like an area where Project Haystack could add some value. Project Haystack is an open source initiative that has developed naming conventions and taxonomies for building equipment and operational data. Standardizing addressing formats and binding addresses of data points to other objects in a building or buildings facilitates integration of the data and enriches the context of the data point by incorporating related data. 4. Configuration BAMie is ambitious in documenting automation and control system configurations. The idea is to make the information exchange between the system contractor, other designers, contractors and the facility manager or building owner more efficient. Configuration data can include data such as set points for specific building spaces, schedules, even alarm conditions. The usefulness of documenting system configurations for information exchange may depend on the specific automation and control system, specifically the management workstations of the system, where configurations can be set. 5. Performance The proposed model definition for performance is interesting. Because BAMie data includes relationships between objects and artifacts and can produce a fluent exchange of data, it can facilitate the creation of performance metrics that an automation and control system would not be able to do, for example creating 3D models or color coded floor plans of energy consumption trends over a time series. 3
The building automation industry is abuzz with data analytics. Analytic software solutions for complex HVAC systems have shown substantial benefits in operations and energy management. The key is data. The proposed BAMie is not only a repository for comprehensive data in automation and control systems, but it provides a means that the data can be easily exchanged with other systems and other various colleagues involved in design, construction and operation of the building. The building automation industry needs to embrace and support the BAMie effort. Construction Directors and Facility Managers should request designers and contractors provide system data and submittals in electronic format. Finally, the industry experience with BIM and information exchange to date is somewhat isolated to just architects, design engineers and construction companies. Not many facility management organizations have consumed and used BIM data despite the fact that the greatest benefits of BIM are in building operations. There are a number of facility management systems that can import BIM and populate FM applications such as asset management, preventative maintenance and document management. 4
If we can acquire automation and control system data digitally in the proposed format from the start of a project, enrich the data with digital relationships within the building, coordinate it with other designers and finally populate our facility management systems, we will be on the road to better building performance. For more information, write us at info@smart-buildings.com. Photos courtesy of Google and Bing Images 5