First Commit

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commit 17a9c69379
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+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2022 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Manage construction and maintenance resources
+
+Resources include equipment (cranes, etc), labour, material, and products. They
+are typically referenced in construction planning, maintenance schedules, or
+cost items.
+"""
+
+from .. import wrap_usecases
+from .add_resource import add_resource
+from .add_resource_quantity import add_resource_quantity
+from .add_resource_time import add_resource_time
+from .assign_resource import assign_resource
+from .calculate_resource_usage import calculate_resource_usage
+from .calculate_resource_work import calculate_resource_work
+from .edit_resource import edit_resource
+from .edit_resource_quantity import edit_resource_quantity
+from .edit_resource_time import edit_resource_time
+from .remove_resource import remove_resource
+from .remove_resource_quantity import remove_resource_quantity
+from .unassign_resource import unassign_resource
+
+wrap_usecases(__path__, __name__)
+
+__all__ = [
+    "add_resource",
+    "add_resource_quantity",
+    "add_resource_time",
+    "assign_resource",
+    "calculate_resource_usage",
+    "calculate_resource_work",
+    "edit_resource",
+    "edit_resource_quantity",
+    "edit_resource_time",
+    "remove_resource",
+    "remove_resource_quantity",
+    "unassign_resource",
+]
@@ -0,0 +1,89 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+from typing import Optional
+
+import ifcopenshell.api.nest
+import ifcopenshell.api.project
+import ifcopenshell.api.root
+
+
+def add_resource(
+    file: ifcopenshell.file,
+    parent_resource: Optional[ifcopenshell.entity_instance] = None,
+    ifc_class: str = "IfcCrewResource",
+    name: Optional[str] = None,
+    predefined_type: str = "NOTDEFINED",
+) -> ifcopenshell.entity_instance:
+    """Add a new construction resource
+
+    Construction resources may be managed and connected to cost schedules
+    and construction schedules. This allows calculations to be done on
+    resource utilisation, cost optimisation (e.g. labour rates), and
+    optioneering on build strategies.
+
+    There are typically two types of resources. Crew resources are resources
+    where you manage your own crew and you have full control over the
+    equipment, labour, products, and materials used by your crew.
+    Alternatively, there are subcontractor resources, where you simply
+    delegate all the details to a subcontractor and it is not decomposed
+    into further levels of detail.
+
+    This means when adding resources, you'd first either add a crew or
+    subcontract resource. If it is a crew resource, you'd then add child
+    resources to that crew, such as equipment (cranes, excavators, hoists,
+    etc), material (wood, concrete, etc), and labour (rigging crews,
+    formworkers, etc).
+
+    :param parent_resource: If this is a child resource (typically to a crew
+        resource), then nominate the parent IfcConstructionResource here.
+    :param ifc_class: The class of resource chosen from
+        IfcConstructionEquipmentResource, IfcConstructionMaterialResource,
+        IfcConstructionProductResource, IfcCrewResource, IfcLaborResource,
+        or IfcSubContractResource.
+    :param name: The name of the resource
+    :param predefined_type: Consult the IFC documentation for the valid
+        predefined types for each type of resource class.
+    :return: The newly created resource depending on the nominated IFC
+        class.
+
+    Example:
+
+    .. code:: python
+
+        # Add our own crew
+        crew = ifcopenshell.api.resource.add_resource(model, ifc_class="IfcCrewResource")
+
+        # Add some labour to our crew.
+        ifcopenshell.api.resource.add_resource(model, parent_resource=crew, ifc_class="IfcLaborResource")
+    """
+
+    resource = ifcopenshell.api.root.create_entity(
+        file,
+        ifc_class=ifc_class,
+        predefined_type=predefined_type,
+        name=name or "Unnamed",
+    )
+    # TODO: this is an ambiguity by buildingSMART: Can we nest an IfcCrewResource under an IfcCrewResource ?
+    # https://forums.buildingsmart.org/t/what-are-allowed-to-be-root-level-construction-resources/3550
+    if parent_resource:
+        ifcopenshell.api.nest.assign_object(file, related_objects=[resource], relating_object=parent_resource)
+    elif file.schema != "IFC2X3":
+        context = file.by_type("IfcContext")[0]
+        ifcopenshell.api.project.assign_declaration(file, definitions=[resource], relating_context=context)
+    return resource
@@ -0,0 +1,83 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import ifcopenshell.util.element
+import ifcopenshell.util.resource
+
+
+def add_resource_quantity(
+    file: ifcopenshell.file, resource: ifcopenshell.entity_instance, ifc_class: str = "IfcQuantityCount"
+) -> ifcopenshell.entity_instance:
+    """Adds a quantity to a resource
+
+    The quantity of a resource represents the "unit quantity" of that
+    resource. For example, labour might be hired on a daily basis (8 hours).
+    There are different types of quantities (e.g. volume, count, or time).
+    Which quantity is used depends on the type of resource.  Material
+    resources may be quantified in terms of length, area, volume, or weight.
+    Equipment and labour resources are quantified in terms of time. Products
+    resources are quantified in terms of counts.
+
+    This base quantity is then used in other calculations.
+
+    :param resource: The IfcConstructionResource to add a quantity to.
+    :param ifc_class: The type of quantity to add, chosen from
+        IfcQuantityArea (for material), IfcQuantityCount (for products),
+        IfcQuantityLength (for material), IfcQuantityTime (for equipment or
+        labour), IfcQuantityVolume (for material), and IfcQuantityWeight
+        (for material).
+    :return: The newly created quantity depending on the IFC class
+
+    Example:
+
+    .. code:: python
+
+        # Add our own crew
+        crew = ifcopenshell.api.resource.add_resource(model, ifc_class="IfcCrewResource")
+
+        # Add some labour to our crew.
+        labour = ifcopenshell.api.resource.add_resource(model,
+            parent_resource=crew, ifc_class="IfcLaborResource")
+
+        # Labour resource is quantified in terms of time.
+        quantity = ifcopenshell.api.resource.add_resource_quantity(model,
+            resource=labour, ifc_class="IfcQuantityTime")
+
+        # Store the time used in hours
+        ifcopenshell.api.resource.edit_resource_quantity(model,
+            physical_quantity=quantity, attributes={"TimeValue": 8.0})
+    """
+    resource_type = resource.is_a()
+    supported_quantities = ifcopenshell.util.resource.RESOURCES_TO_QUANTITIES[resource_type]
+    if ifc_class not in supported_quantities:
+        raise ValueError(
+            f"Resource type '{resource_type}' does not support quantity type '{ifc_class}'. "
+            f"Supported quantities: {','.join(supported_quantities)}"
+        )
+
+    quantity = file.create_entity(ifc_class, Name="Unnamed")
+    # 3 IfcPhysicalSimpleQuantity Value
+    if ifc_class == "IfcQuantityCount":
+        quantity[3] = 0
+    else:
+        quantity[3] = 0.0
+    old_quantity = resource.BaseQuantity
+    resource.BaseQuantity = quantity
+    if old_quantity:
+        ifcopenshell.util.element.remove_deep2(file, old_quantity)
+    return quantity
@@ -0,0 +1,59 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import ifcopenshell.util.date
+
+
+def add_resource_time(file: ifcopenshell.file, resource: ifcopenshell.entity_instance) -> ifcopenshell.entity_instance:
+    """Adds the time that a resource is used for
+
+    For labour and equipment resources, the total duration that the resource
+    is used for may be stored. This may either be input manually or
+    calculated parametrically. This is known as the resource time, and may
+    be used to calculate other parameters like resource utilisation.
+
+    :param resource: The IfcConstructionResource to record time for.
+    :return: The newly created IfcResourceTime
+
+    Example:
+
+    .. code:: python
+
+        # Add our own crew
+        crew = ifcopenshell.api.resource.add_resource(model, ifc_class="IfcCrewResource")
+
+        # Add some labour to our crew.
+        labour = ifcopenshell.api.resource.add_resource(model,
+            parent_resource=crew, ifc_class="IfcLaborResource")
+
+        # Labour resource is quantified in terms of time.
+        quantity = ifcopenshell.api.resource.add_resource_quantity(model,
+            resource=labour, ifc_class="IfcQuantityTime")
+
+        # Store the unit time used in hours
+        ifcopenshell.api.resource.edit_resource_quantity(model,
+            physical_quantity=quantity, attributes={"TimeValue": 8.0})
+
+        # Let's imagine we've used the resource for 2 days.
+        time = ifcopenshell.api.resource.add_resource_time(model, resource=labour)
+        ifcopenshell.api.resource.edit_resource_time(model,
+            resource_time=time, attributes={"ScheduleWork": "PT16H"})
+    """
+    resource_time = file.create_entity("IfcResourceTime")
+    resource.Usage = resource_time
+    return resource_time
@@ -0,0 +1,106 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import ifcopenshell
+import ifcopenshell.api.owner
+import ifcopenshell.guid
+
+
+def assign_resource(
+    file: ifcopenshell.file,
+    relating_resource: ifcopenshell.entity_instance,
+    related_object: ifcopenshell.entity_instance,
+) -> ifcopenshell.entity_instance:
+    """Assigns a resource to an object
+
+    Two types of objects are typically assigned to resources: products and
+    actors.
+
+    If a product is assigned to a resource, that means that the product
+    represents the resource on site. This may be represented via material
+    handling zones on a construction site, or equipment like cranes and
+    their physical locations.
+
+    If an actor is assigned to a resource, that means that the actor (person
+    or organisation) is the actor consuming the resource (e.g. if the
+    resource is material or equipment) or the actor performing the work
+    (e.g. if the resource is a labour resource).
+
+    :param relating_resource: The IfcResource to assign the object to.
+    :param related_object: The IfcProduct or IfcActor to assign to the
+        object.
+    :return: The newly created IfcRelAssignsToResource
+
+    Example:
+
+    .. code:: python
+
+        # Add our own crew
+        crew = ifcopenshell.api.resource.add_resource(model, ifc_class="IfcCrewResource")
+
+        # Add some a tower crane to our crew.
+        crane = ifcopenshell.api.resource.add_resource(model,
+            parent_resource=crew, ifc_class="IfcConstructionEquipmentResource", name="Tower Crane 01")
+
+        # Our tower crane will be placed via this physical product.
+        product = ifcopenshell.api.root.create_entity(model,
+            ifc_class="IfcBuildingElementProxy", predefined_type="CRANE")
+
+        # Let's place our crane at some X, Y coordinates.
+        matrix = numpy.eye(4)
+        matrix[0][3], matrix[1][3] = 3.0, 4.0
+        ifcopenshell.api.geometry.edit_object_placement(model, product=crane, matrix=matrix)
+
+        # Let's assign our crane to the resource. The crane now represents
+        # the resource.
+        ifcopenshell.api.resource.assign_resource(model, relating_resource=crane, related_object=product)
+
+        # Setup an organisation actor who will operate the crane
+        organisation = ifcopenshell.api.owner.add_organisation(model,
+            identification="UCO", name="Unionised Crane Operators Pty Ltd")
+        role = ifcopenshell.api.owner.add_role(model, assigned_object=organisation, role="CREW")
+        actor = ifcopenshell.api.owner.add_actor(model, actor=organisation)
+
+        # This means that UCO is now our crane operator.
+        ifcopenshell.api.resource.assign_resource(model, relating_resource=crane, related_object=actor)
+    """
+    if related_object.HasAssignments:
+        for assignment in related_object.HasAssignments:
+            if assignment.is_a("IfclRelAssignsToResource") and assignment.RelatingResource == relating_resource:
+                return assignment
+
+    resource_of = None
+    if relating_resource.ResourceOf:
+        resource_of = relating_resource.ResourceOf[0]
+
+    if resource_of:
+        related_objects = list(resource_of.RelatedObjects)
+        related_objects.append(related_object)
+        resource_of.RelatedObjects = related_objects
+        ifcopenshell.api.owner.update_owner_history(file, element=resource_of)
+    else:
+        resource_of = file.create_entity(
+            "IfcRelAssignsToResource",
+            **{
+                "GlobalId": ifcopenshell.guid.new(),
+                "OwnerHistory": ifcopenshell.api.owner.create_owner_history(file),
+                "RelatedObjects": [related_object],
+                "RelatingResource": relating_resource,
+            }
+        )
+    return resource_of
@@ -0,0 +1,54 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+
+import ifcopenshell.api
+import ifcopenshell.util.constraint
+import ifcopenshell.util.date
+import ifcopenshell.util.resource
+
+
+def calculate_resource_usage(file: ifcopenshell.file, resource: ifcopenshell.entity_instance) -> None:
+    """Calculates the number of resources required to perform scheduled work on a task.
+
+    :param resource: The IfcConstructionResource to calculate the usage for.
+    :return: None
+    """
+
+    if ifcopenshell.util.constraint.is_attribute_locked(resource, "Usage.ScheduleUsage"):
+        return
+    if not resource.Usage or not resource.Usage.ScheduleWork:
+        return
+
+    task = ifcopenshell.util.resource.get_task_assignments(resource)
+    if not task or not task.TaskTime:
+        return
+
+    if not task.TaskTime.DurationType or task.TaskTime.DurationType == "WORKTIME":
+        hours_per_day = 8
+    else:
+        hours_per_day = 24
+
+    task_duration = ifcopenshell.util.date.ifc2datetime(task.TaskTime.ScheduleDuration)
+    seconds = task_duration.days * hours_per_day * 60 * 60
+    seconds += task_duration.seconds
+
+    person_hours = ifcopenshell.util.date.ifc2datetime(resource.Usage.ScheduleWork)
+
+    required_resources = person_hours.total_seconds() / seconds
+    resource.Usage.ScheduleUsage = float(required_resources)
@@ -0,0 +1,61 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import ifcopenshell.api.resource
+import ifcopenshell.util.constraint
+import ifcopenshell.util.resource
+
+
+def calculate_resource_work(file: ifcopenshell.file, resource: ifcopenshell.entity_instance) -> None:
+    """Calculates the work that a resource is used for
+
+    This is an unofficial parametric calculation that may be done on a
+    resource based on careful analysis of the relationships between the
+    costing, scheduling, and resource domains in IFC.
+
+    A resource may store a productivity rate in a property set called
+    EPset_Productivity. This stores three properties:
+
+    * BaseQuantityConsumed - a duration that the resource is consumed for.
+    * BaseQuantityProducedName - what quantity the resource can produce,
+        such as area or volume.
+    * BaseQuantityProducedValue - what value of that quantity the resource
+        can produce during that duration.
+
+    For example, a labour or equipment resource might produce 100m3 of
+    NetVolume every day (i.e. 8 hours are consumed).
+
+    Then, if a resource is assigned to a construction task, and that
+    construction task is assigned to concrete slabs totalling 200m3, we can
+    calculate that the resource consumes 16 hours of work.
+
+    This calculated work is stored against the resource as scheduled work
+    under the resource time data.
+
+    :param resource: The IfcConstructionResource that you want to calculate
+        the work performed.
+    :return None:
+    """
+    if ifcopenshell.util.constraint.is_attribute_locked(resource, "Usage.ScheduleWork"):
+        return
+    amount_worked = ifcopenshell.util.resource.get_resource_required_work(resource)
+    if not amount_worked:
+        return
+    if not resource.Usage:
+        ifcopenshell.api.resource.add_resource_time(file, resource=resource)
+    resource.Usage.ScheduleWork = amount_worked
@@ -0,0 +1,44 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+from typing import Any
+
+import ifcopenshell
+
+
+def edit_resource(file: ifcopenshell.file, resource: ifcopenshell.entity_instance, attributes: dict[str, Any]) -> None:
+    """Edits the attributes of an IfcResource
+
+    For more information about the attributes and data types of an
+    IfcResource, consult the IFC documentation.
+
+    :param resource: The IfcResource entity you want to edit
+    :param attributes: a dictionary of attribute names and values.
+    :return: None
+
+    Example:
+
+    .. code:: python
+
+        # Add our own crew
+        crew = ifcopenshell.api.resource.add_resource(model, ifc_class="IfcCrewResource")
+
+        # Change the name of the resource to "Zone A Crew"
+        ifcopenshell.api.resource.edit_resource(model, resource=resource, attributes={"Name": "Foo"})
+    """
+    for name, value in attributes.items():
+        setattr(resource, name, value)
@@ -0,0 +1,55 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+from typing import Any
+
+import ifcopenshell
+
+
+def edit_resource_quantity(
+    file: ifcopenshell.file, physical_quantity: ifcopenshell.entity_instance, attributes: dict[str, Any]
+) -> None:
+    """Edits the attributes of an IFC quantity
+
+    For more information about the attributes and data types of an
+    IfC quantity, consult the IFC documentation.
+
+    :param physical_quantity: The IfC quantity entity you want to edit
+    :param attributes: a dictionary of attribute names and values.
+    :return: None
+
+    Example:
+
+    .. code:: python
+
+        # Add our own crew
+        crew = ifcopenshell.api.resource.add_resource(model, ifc_class="IfcCrewResource")
+
+        # Add some labour to our crew.
+        labour = ifcopenshell.api.resource.add_resource(model,
+            parent_resource=crew, ifc_class="IfcLaborResource")
+
+        # Labour resource is quantified in terms of time.
+        ifcopenshell.api.resource.add_resource_quantity(model,
+            resource=labour, ifc_class="IfcQuantityTime")
+
+        # Store the time used in hours
+        ifcopenshell.api.resource.edit_resource_quantity(model,
+            physical_quantity=time, attributes={"TimeValue": 8.0})
+    """
+    for name, value in attributes.items():
+        setattr(physical_quantity, name, value)
@@ -0,0 +1,99 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+from typing import Any
+
+import ifcopenshell
+import ifcopenshell.api.sequence
+import ifcopenshell.util.constraint
+import ifcopenshell.util.date
+import ifcopenshell.util.resource
+
+
+def edit_resource_time(
+    file: ifcopenshell.file, resource_time: ifcopenshell.entity_instance, attributes: dict[str, Any]
+) -> None:
+    """Edits the attributes of an IfcResourceTime
+
+    For more information about the attributes and data types of an
+    IfcResourceTime, consult the IFC documentation.
+
+    :param resource_time: The IfcResourceTime entity you want to edit
+    :param attributes: a dictionary of attribute names and values.
+    :return: None
+
+    Example:
+
+    .. code:: python
+
+        # Add our own crew
+        crew = ifcopenshell.api.resource.add_resource(model, ifc_class="IfcCrewResource")
+
+        # Add some labour to our crew.
+        labour = ifcopenshell.api.resource.add_resource(model,
+            parent_resource=crew, ifc_class="IfcLaborResource")
+
+        # Labour resource is quantified in terms of time.
+        ifcopenshell.api.resource.add_resource_quantity(model,
+            resource=labour, ifc_class="IfcQuantityTime")
+
+        # Store the unit time used in hours
+        ifcopenshell.api.resource.edit_resource_quantity(model,
+            physical_quantity=time, attributes={"TimeValue": 8.0})
+
+        # Let's imagine we've used the resource for 2 days.
+        time = ifcopenshell.api.resource.add_resource_time(model, resource=labour)
+        ifcopenshell.api.resource.edit_resource_time(model,
+            resource_time=time, attributes={"ScheduleWork": "P16H"})
+    """
+    usecase = Usecase()
+    usecase.file = file
+    return usecase.execute(resource_time, attributes)
+
+
+class Usecase:
+    file: ifcopenshell.file
+
+    def execute(self, resource_time: ifcopenshell.entity_instance, attributes: dict[str, Any]) -> None:
+        resource = self.get_resource(resource_time)
+
+        # If the user specifies both an end date and a duration, the duration takes priority
+        if attributes.get("ScheduleWork", None) and "ScheduleFinish" in attributes.keys():
+            del attributes["ScheduleFinish"]
+        if attributes.get("ActualWork", None) and "ActualFinish" in attributes.keys():
+            del attributes["ActualFinish"]
+
+        for name, value in attributes.items():
+            metrics = ifcopenshell.util.constraint.get_metric_constraints(resource, "Usage." + name)
+            if metrics and ifcopenshell.util.constraint.is_hard_constraint(metrics[0]):
+                continue
+            if value:
+                if "Start" in name or "Finish" in name or name == "StatusTime":
+                    value = ifcopenshell.util.date.datetime2ifc(value, "IfcDateTime")
+                elif name == "ScheduleWork" or name == "ActualWork" or name == "RemainingTime":
+                    value = ifcopenshell.util.date.datetime2ifc(value, "IfcDuration")
+            setattr(resource_time, name, value)
+            if name == "ScheduleUsage" and ifcopenshell.util.constraint.get_metric_constraints(
+                resource, "Usage.ScheduleWork"
+            ):
+                task = ifcopenshell.util.resource.get_task_assignments(resource)
+                if task:
+                    ifcopenshell.api.sequence.calculate_task_duration(self.file, task=task)
+
+    def get_resource(self, resource_time: ifcopenshell.entity_instance) -> ifcopenshell.entity_instance:
+        return next(e for e in self.file.get_inverse(resource_time) if e.is_a("IfcResource"))
@@ -0,0 +1,78 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021-2022, Dion Moult <dion@thinkmoult.com>, Yassine Oualid <yassine@sigmadimensions.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import ifcopenshell
+import ifcopenshell.api.resource
+import ifcopenshell.util.element
+
+
+def remove_resource(file: ifcopenshell.file, resource: ifcopenshell.entity_instance) -> None:
+    """Removes a resource and all relationships
+
+    Example:
+
+    .. code:: python
+
+        # Add our own crew
+        crew = ifcopenshell.api.resource.add_resource(model, ifc_class="IfcCrewResource")
+
+        # Fire our crew
+        ifcopenshell.api.resource.remove_resource(model, resource=crew)
+    """
+    settings = {"resource": resource}
+
+    def remove_consider_history(root: ifcopenshell.entity_instance) -> None:
+        history = root.OwnerHistory
+        file.remove(root)
+        if history:
+            ifcopenshell.util.element.remove_deep2(file, history)
+
+    # TODO: review deep purge
+    for inverse in file.get_inverse(settings["resource"]):
+        if inverse.is_a("IfcRelNests"):
+            if inverse.RelatingObject == settings["resource"]:
+                # Remove rel before iteration over objects
+                # to simplify removal of nested resources and avoid crashes.
+                related_objects = inverse.RelatedObjects
+                remove_consider_history(inverse)
+                for related_object in related_objects:
+                    ifcopenshell.api.resource.remove_resource(file, resource=related_object)
+            elif inverse.RelatedObjects == (resource,):
+                remove_consider_history(inverse)
+
+        elif inverse.is_a("IfcRelAssignsToControl"):
+            if len(inverse.RelatedObjects) == 1:
+                remove_consider_history(inverse)
+            else:
+                related_objects = list(inverse.RelatedObjects)
+                related_objects.remove(settings["resource"])
+                inverse.RelatedObjects = related_objects
+        elif inverse.is_a("IfcRelAssignsToResource"):
+            if inverse.RelatingResource == settings["resource"]:
+                for related_object in inverse.RelatedObjects:
+                    ifcopenshell.api.resource.unassign_resource(
+                        file, related_object=related_object, relating_resource=settings["resource"]
+                    )
+            elif inverse.RelatedObjects == (resource,):
+                remove_consider_history(inverse)
+    # Usage was added in IFC4.
+    if usage := getattr(settings["resource"], "Usage", None):
+        file.remove(usage)
+    if settings["resource"].BaseQuantity:
+        ifcopenshell.api.resource.remove_resource_quantity(file, resource=settings["resource"])
+    remove_consider_history(resource)
@@ -0,0 +1,50 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import ifcopenshell.util.element
+
+
+def remove_resource_quantity(file: ifcopenshell.file, resource: ifcopenshell.entity_instance) -> None:
+    """Removes the base quantity of a resource
+
+    :param resource: The IfcConstructionResource to remove the quantity from.
+    :return: None
+
+    Example:
+
+    .. code:: python
+
+        # Add our own crew
+        crew = ifcopenshell.api.resource.add_resource(model, ifc_class="IfcCrewResource")
+
+        # Add some labour to our crew.
+        labour = ifcopenshell.api.resource.add_resource(model,
+            parent_resource=crew, ifc_class="IfcLaborResource")
+
+        # Labour resource is quantified in terms of time.
+        ifcopenshell.api.resource.add_resource_quantity(model,
+            resource=labour, ifc_class="IfcQuantityTime")
+
+        # Let's say we only want to store the resource but no quantities,
+        # let's clean up our mess and remove the quantity.
+        ifcopenshell.api.resource.remove_resource_quantity(model, resource=labour)
+    """
+    old_quantity = resource.BaseQuantity
+    resource.BaseQuantity = None
+    if old_quantity:
+        ifcopenshell.util.element.remove_deep2(file, old_quantity)
@@ -0,0 +1,72 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import ifcopenshell
+import ifcopenshell.api.owner
+import ifcopenshell.util.element
+
+
+def unassign_resource(
+    file: ifcopenshell.file,
+    relating_resource: ifcopenshell.entity_instance,
+    related_object: ifcopenshell.entity_instance,
+) -> None:
+    """Removes the relationship between a resource and object
+
+    :param relating_resource: The IfcResource to assign the object to.
+    :param related_object: The IfcProduct or IfcActor to assign to the
+        object.
+    :return: None
+
+    Example:
+
+    .. code:: python
+
+        # Add our own crew
+        crew = ifcopenshell.api.resource.add_resource(model, ifc_class="IfcCrewResource")
+
+        # Add some a tower crane to our crew.
+        crane = ifcopenshell.api.resource.add_resource(model,
+            parent_resource=crew, ifc_class="IfcConstructionEquipmentResource", name="Tower Crane 01")
+
+        # Our tower crane will be placed via this physical product.
+        product = ifcopenshell.api.root.create_entity(model,
+            ifc_class="IfcBuildingElementProxy", predefined_type="CRANE")
+
+        # Let's assign our crane to the resource. The crane now represents
+        # the resource.
+        ifcopenshell.api.resource.assign_resource(model,
+            relating_resource=crane, related_object=product)
+
+        # Undo it.
+        ifcopenshell.api.resource.unassign_resource(model,
+            relating_resource=crane, related_object=product)
+    """
+    for rel in related_object.HasAssignments or []:
+        if not rel.is_a("IfcRelAssignsToResource") or rel.RelatingResource != relating_resource:
+            continue
+        if len(rel.RelatedObjects) == 1:
+            history = rel.OwnerHistory
+            file.remove(rel)
+            if history:
+                ifcopenshell.util.element.remove_deep2(file, history)
+            return
+        related_objects = list(rel.RelatedObjects)
+        related_objects.remove(related_object)
+        rel.RelatedObjects = related_objects
+        ifcopenshell.api.owner.update_owner_history(file, element=rel)