The IfcProcessExtension schema provides the primary information that expands one of the key ideas of the IFC Model. This is the idea of 'process' which captures ideas about the planning and scheduling of work. It is important to understand that process information can be expressed by classes in exactly the same way as product information. A process can also have state and identity, the state being determined by the values of various attributes of the processes.

Scope

The IfcProcessExtension schema forms part of the Core Layer of the IFC Model. It extends the primary idea of the IfcProcess outlined in the IfcKernel schema. The objective of the IfcProcessExtension schema is to capture information that supports the planning and scheduling of work and the resources required to carry out work. The aim is to provide support for information exchange and sharing within commonly used scheduling applications; the extent of the model will not support the more detailed ideas found in more specialized scheduling applications.

The following are within the scope of this part of the specifications:

• Definition of work plans including the tasks that are included within the plan and identification of the resources required by the plan.
• Definition of work schedules together with the elements that make up the schedule, the time constraints and durations applicable to the elements.
• Identification of work tasks included in plans and schedules
• Identification of the relationship between a process and the resources that are consumed by the process.
• Allocation of resources to work plans, work schedules and work tasks

see attached document for more on process usage