Module Contents#

class ifcopenshell.api.sequence.add_task.Usecase(file, work_schedule=None, parent_task=None, name=None, description=None, identification=None, predefined_type='NOTDEFINED')#

Adds a new task

Tasks are typically used for two purposes: construction scheduling and facility management.

In construction scheduling, a task represents a job to be done in a work schedule. Tasks are organised in a hierarchical manner known as a work breakdown structure (WBS) and have lots of sequential relationships (e.g. this task must finish before the next task can start) and date information (e.g. durations, start dates). This is often represented as a gantt chart and used to analyse critical paths to try and reduce project time to stay on-time and within budget.

In facility management, a task represents a maintenance task to maintain a piece of equipment. Tasks are broken down into a punch list, or simply a bulleted or ordered sequence of tasks to be performed (e.g. turn off equipment, check power connection, etc) in order to maintain the equipment. Tasks will also typically have recurring scheduled dates in line with the maintenance schedule. These maintenance tasks and procedures are typically published as part of an operations and maintenance manual.

All tasks must be grouped in a work schedule, either directly as a root or top-level task, or indirectly as a child or subtask of a parent task. In construction scheduling, tasks may be nested many times to create the work breakdown structure, and the “leaf” tasks (i.e. tasks with no more subtasks) are considered to be the activities with dates, whereas all parent tasks are part of the breakdown structure used for categorisation purposes. In facility management, top-level tasks represent the overall maintenance job to be performed, and child tasks represent an ordered list of things to do for that maintenance. These form a 2-level hierarchy. No further child tasks are recommended.

  • work_schedule (ifcopenshell.entity_instance.entity_instance) – The work schedule to group the task in, if the task is to be a top-level or root task. This is mutually exclusive with the parent_task parameter.

  • parent_task (ifcopenshell.entity_instance.entity_instance) – The parent task, if the task is to be a subtask or child task. This is mutually exclusive with the work_schedule parameter.

  • name (str,optional) – The name of the task.

  • description (str,optional) – The description of the task.

  • identification (str,optional) – The identification code of the task.

  • predefined_type (str) – The predefined type of the task. Common ones include CONSTRUCTION, DEMOLITION, or MAINTENANCE. Consultant the IFC documentation for IfcTaskTypeEnum for more information.


The newly created IfcTask

Return type



# Let's imagine we are creating a construction schedule. All tasks
# need to be part of a work schedule.
schedule = ifcopenshell.api.run("sequence.add_work_schedule", model, name="Construction Schedule A")

# Add a root task to represent the design milestones, and major
# project phases.
ifcopenshell.api.run("sequence.add_task", model,
    work_schedule=schedule, name="Milestones", identification="A")
ifcopenshell.api.run("sequence.add_task", model,
    work_schedule=schedule, name="Design", identification="B")
construction = ifcopenshell.api.run("sequence.add_task", model,
    work_schedule=schedule, name="Construction", identification="C")

# Let's start creating our work breakdown structure.
ifcopenshell.api.run("sequence.add_task", model,
    parent_task=construction, name="Early Works", identification="C1")
ifcopenshell.api.run("sequence.add_task", model,
    parent_task=construction, name="Substructure", identification="C2")
superstructure = ifcopenshell.api.run("sequence.add_task", model,
    parent_task=construction, name="Superstructure", identification="C3")

# Notice how the leaf task is the actual activity
ifcopenshell.api.run("sequence.add_task", model,
    parent_task=superstructure, name="Ground Floor FRP", identification="C3.1")

# Let's imagine we are digitising an operations and maintenance
# manual for the mechanical discipline.
maintenance = ifcopenshell.api.run("sequence.add_work_schedule", model, name="Mechanical Maintenance")

# Imagine we have to clean the condenser coils for a chiller every
# month. Like the schedule above, to keep things simple we won't
# show scheduling times and calendars. This root task represents the
# overall maintenance task.
cleaning = ifcopenshell.api.run("sequence.add_task", model,
    work_schedule=maintenance, name="Condenser coil cleaning")

# These subtasks represent the punch list of maintenance tasks.
ifcopenshell.api.run("sequence.add_task", model, parent_task=cleaning, identification="1",
    description="Prior to work, wear safety shoes, gloves, and goggles.")
ifcopenshell.api.run("sequence.add_task", model, parent_task=cleaning, identification="2",
    description="Prepare jet pump, screwdriver, hose clamp, and control panel door key.")
ifcopenshell.api.run("sequence.add_task", model, parent_task=cleaning, identification="3",
    description="Switch OFF the chiller unit.")
ifcopenshell.api.run("sequence.add_task", model, parent_task=cleaning, identification="3",
    description="Open the isolator switch.")
ifcopenshell.api.run("sequence.add_task", model, parent_task=cleaning, identification="3",
    description="Setup the water pressure by tapping to a water supply and connecting to a ...")