> For the complete documentation index, see [llms.txt](https://virtualfactory.gitbook.io/vlft/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://virtualfactory.gitbook.io/vlft/kb/fdm/owl-classes.md). # OWL Classes This section presents more details of the Factory Data Model in terms of OWL classes that are useful to [instantiate factory models](/vlft/kb/instantiation.md) while going through the [ontology modules](/vlft/kb/fdm.md#modular-architecture). ## **statistics** The **statistics module** represents basic probability distributions via semantic characterization of key parameters**.** Representation of descriptive statistics. ![](/files/-MVRVrC_z0qIt8OScYT9) ## **expression** The **expression module** formalizes Algebraic and Logical expressions. An expression can be decomposed in atomic, unary, binary, iterated binary, control flow expressions. ![](/files/-MVRZCi5iiG2RQv12vi7) ## **osph** The **osph module** models Object States and Performance History, while integrating the ontology modules fsm, statistics, ssn, sosa, expression. ![](/files/-MVRZUk_pRVcmOf4PQas) ## **IFC4\_ADD1 and IFC4\_ADD1\_extension** The **ifcOWL ontology** consists of three main classes: ifc:IfcContext, ifc:IfcObject, ifc:IfcTypeObject. ![](/files/-MVRflq33S8h9VAv-ybe) The following table lists some subclasses of ifc:IfctObject that can be exploited to model a factory. If available, a subclass of ifc:IfcTypeObject is paired with the corresponding sublcass of ifc:IfctObject, as it can be exploited according to the [object typing pattern](/vlft/kb/fdm.md#object-typing-pattern). **ifc:** prefix stands for |

Subclass of

ifc:IfcObject

| Description |

Subclass of

ifc:IfctTypeObject

| | --------------------------------------- | ----------------------------------------------- | -------------------------------------------- | | ifc:IfcBuilding | Building | | | ifc:IfcDoor | Door | ifc:IfcDoorType | | ifc:IfcColumn | Column of a building | ifc:IfcColumnType | | ifc:IfcRoof | Roof of a building | ifc:IfcRoofType | | ifc:IfcWall | Wall of a building | ifc:IfcWallType | | ifc:IfcWindow | Window of a building | ifc:IfcWindowType | | ifc:IfcSensor | Sensor subclass also of sosa:Sensor | ifc:IfcSensorType | | ifc:IfcActuator | Actuator subclass also of sosa:Actuator | ifc:IfcActuatorType | | ifc:IfcElementAssembly | Complex element assembly | ifc:IfcElementAssemblyType | | ifc:IfcIfcTransportElement | Generalization of all transport related objects | ifc:IfcTransportElementType | | ifc:IfcTask | Unit of work | ifc:IfcTaskType | ## **factory** The **factory module** specializes IFC\_ADD1 and controlSystem modules with definitions related to production processes, part types, manufacturing systems and machine tools. The following tables list some subclasses of ifc:IfctObject that can be exploited to model a factory. If available, a subclass of ifc:IfcTypeObject is paired with the corresponding sublcass of ifc:IfctObject, as it can be exploited according to the [object typing pattern](/vlft/kb/fdm.md#object-typing-pattern). **fa:** prefix stands for |

Subclass of

ifc:IfcProduct

| Description |

Subclass of

ifc:IfctTypeProduct

| | ---------------------------------------- | ------------------------------------------------------------------------------------------------ | --------------------------------------------- | | fa:Artifact | Part that is the result of a production activity | fa:ArtifactType | | fa:BufferElement | Object or space dedicated to hosting objects (e.g. artifacts, pallets) | fa:BufferElementType | | fa:MachineTool | Generic machine tool | fa:MachineToolType | | fa:Robot | Robot | fa:RobotType | | fa:Pallet | Object dedicated to hosting artifacts that are transported in a system (e.g. production system). | fa:PalletType | | fa:Tool | Tool | fa:ToolType | |

Subclass of

ifc:IfcTask

| Description |

Subclass of

ifc:IfctTaskType

| | ------------------------------------- | ----------------------------------------- | ------------------------------------------ | | fa:AssemblyTask | Task executing an assemby operation. | fa:AssemblyTaskType | | fa:DisassemblyTask | Task executing an disassemby operation. | fa:DisassemblyTaskType | | fa:MaintenanceTask | Task executing a maintenance operation. | fa:MaintenanceTaskType | | fa:ManufacturingTask | Task executing a manufacturing operation. | fa:ManufacturingTaskType | | fa:MachiningTask | Task executing a manufacturing operation. | fa:MachiningTaskType | | fa:QualityControlTask | Task executing a quality control. | fa:QualityControlTaskType | | fa:TransportTask | Task executing a transportation. | fa:TransportTaskType | |

Subclass of

ifc:IfcControl

| Description | | ---------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------- | | fa:ProductionPlan | Plan of activities to be executed by a production system in terms demanded volume of artifacts, available resources, assignements, adopted control policies | | fa:ProductionSchedule | Component of a fa:ProductionPlan specifying the demanded volumes for a type of artifact | --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://virtualfactory.gitbook.io/vlft/kb/fdm/owl-classes.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.