|buildingSMART alliance Construction Operations Building Information Exchange (COBie): V2.40 Update|
Construction Operations Building Information Exchange (COBie): Version 2.40 Update
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by Nicholas Nisbet MA (Cantab) DipArch (UNL) - AEC3 and E. William East, PhD, PE, F.ASCE - Engineer Research and Development Center, U.S Army, Corps of Engineers
The COBie 2.40 updates established requirements identified since the production of the COBie 2.26 specification. These changes were required to support the United States and international adoption of the Industry Foundation Class Facility Management Handover Model View Definition upon which COBie is based. These changes were previously published for comment and review in 2010.
The first of these changes is the inclusion of standard product information needed for the Specifiers' Properties information exchange project. The second of these changes was the inclusion of the "Assembly" worksheet that allows designers, builders, or manufacturers to specify custom product assemblies such as Air Handling Units or electrical distribution panels. The third change, the addition of the "Issues" worksheet, was required to comply with European standards for the identification of occupational safety and environmental compliance issues. Finally, there are some usage guidelines that were available during COBie 2.26 but now have been made explicit to ensure readability of COBie 2.4 data.
The Version 2.4 updates extend NBIMS-US approved COBie 2.26 required to meet international requirements. These changes will be balloted in a future NBIMS-US voting round. No further changes are expected beyond COBie 2.4.
COBie 2.40 Requirements
1. Product Properties
Requirement: The promotion of open standards for the delivery of installed equipment encourages manufacturers to supply their own product data in an open format rather than have that information be re-keyed by the contractor, commissioning agent, or owner. In the United States the interest in manufacturers' providing their own product data is being fully expressed in the Specifiers' Properties information exchange (SPie) project.
Response: COBie 2.4 provides extra set of fixed properties for Types based on information that is already identified in the FM Handover MVD from the ifcProduct object. These properties are provided as alternatives to using the Attributes table since the properties apply to almost all types of products. The fields should be used to document the nominal and primary characteristics. The first three new fields are numeric and are expected to be given in the common length unit defined for the dataset. No unit string need be given here. The remainder are for textual description of the characteristics of the Type. As with the previous COBie 2.26 version, the Attributes worksheet is used to define more detailed attributes not attributable to all product types.
The following additions are provided to the COBie Type worksheet:
Note: it remains the case that additional fields may be added to the CObie2 dataset where they do not disrupt the schema, which when represented as a spread sheet means to the right of the mandated columns.
Requirement: Some Components, Types or Spaces may be best described as an assembly of other constituents. While this is not always significant from an operational point of view, where it is significant — for example where the constituents may have significant differences in attributes, replacement parts, preventative maintenance schedules or warranty implications — then it may be useful to describe the assembly. Additional information may organize the constituents in order or in space.
Response: Assemblies are now defined in a series of records. First, a COBie.Type record for each type of assembly and each type of equipment in each assembly are needed. This is to reflect differences in replacement parts and maintenance requirements for each of the types of equipment or parts in an assembly. Next, each instance of an assembly and component in an assembly are identified as unique COBie.Components. This is required to ensure that the precise nameplate information, such as serial number and any component-specific testing documents can be explicitly captured. Finally, the COBie 2.4 new worksheet, COBie. Assembly worksheet is provided to allow components to be identified as assemblies. This is required since there are specific properties associated with the assembled product, such as a circuit number, that would not exist outside the content of the assembly.
3. Environmental and Cost Profiling
Requirement: European government requirements mandate the documentation of economic, environmental and even social impacts of a facility or its constituent systems, spaces or types. Whilst the Attribute facility (along with the Type's Replacement Cost and Service Life) can represent these impacts, they are significantly different in that some impacts are incurred before the handover phase (typically capital costs, embedded carbon), whereas others may be incurred during the use (running costs, carbon from fuel usage). Other impacts may be incurred during demolition or re-purposing.
Response: The COBie.Impact worksheet is provide to identify impacts to the facility and its constituent. This will support more detailed analysis of initial and time-based impacts such as those required in European markets.
4. Usage Clarifications
4.a Zone and System Listing
Requirement: Zones and systems play a major part in the management of facilities, and the preparation of the comma delimited lists for the spread sheet representation may be tedious and their visual checking may prove difficult.
Response: COBie 2.4explicitly allows multiple rows to be defined for a Zone or System, each may contain as its Spaces or Components a single name or a comma delimited list of names.
4.b Multiple Classifications and Enumerated Attributes
Requirement: The COBie scenario expects that objects be classified. There may be situations where multiple classifications are available. This may aid support the transitions between functional design, contractual work planning, trade procurement and operational usage. Where COBie2 is being used to communicate a template for facility or product data, some attributes may be specified to be chosen from a predefined list. This additional information can only act as a hint to a COBie2 application or to a receiving application that the attribute may be from a limited set and so, for example, may be useful for filtering the data.
Response: COBie2.30 suggests that an attribute can be given a unit 'classification'. Attributes may also be given a unit 'enumeration', whereupon the allowed values should be provided. In the spread sheet representation column M may be headed 'Allowed Values' and alternatives provided as a comma delimited list.
4.c Object Scoping
Requirement: COBie was specifically aimed at capturing the manageable assets for the owner/operator. As such the published mapping from the FM Handover MVD to the COBie spreadsheet systematically excludes component occurrences that are representing the building structure and component occurrences that are not associated to a named type.
Response: Specific project teams may change mapping rules to relax the constraint that COBie contain only managed assets. This would allow COBie to provide a complete set of structural, architectural partitions and other objects that may be relevant for a particular customer. Users should refer to the IFC to COBie translation tools used to determine if such changes are needed for a given application.