diff --git a/src/ifcopenshell-python/ifcopenshell/api/sequence/add_task.py b/src/ifcopenshell-python/ifcopenshell/api/sequence/add_task.py
new file mode 100644
index 0000000000..c4b7a8061c
--- /dev/null
+++ b/src/ifcopenshell-python/ifcopenshell/api/sequence/add_task.py
@@ -0,0 +1,20 @@
+import ifcopenshell.api
+
+
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {"name": None, "predefined_type": "NOTDEFINED", "is_milestone":False, "identification": "none", "predecessor_to":None, "successor_from":None}
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        task = ifcopenshell.api.run(
+            "root.create_entity",
+            self.file,
+            ifc_class="IfcTask",
+            predefined_type=self.settings["predefined_type"],
+            name=self.settings["name"],
+        )
+        task.IsMilestone = self.settings["is_milestone"]
+        return task
\ No newline at end of file
diff --git a/src/ifcopenshell-python/ifcopenshell/api/sequence/assign_task_predecessor.py b/src/ifcopenshell-python/ifcopenshell/api/sequence/assign_task_predecessor.py
new file mode 100644
index 0000000000..36c0140728
--- /dev/null
+++ b/src/ifcopenshell-python/ifcopenshell/api/sequence/assign_task_predecessor.py
@@ -0,0 +1,25 @@
+import ifcopenshell
+import ifcopenshell.api
+
+
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {
+            "predecessor_task": None,
+            "sequence_type":"FINISH_START",
+            "task": None,            
+        }
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        #TODO: tasks can only have one relationship between oneanother: if a relationship is already assigned, it should overide the previous one's settings.
+        rel_sequence = self.file.create_entity("IfcRelSequence",**{
+                "GlobalId": ifcopenshell.guid.new(),
+                "OwnerHistory": ifcopenshell.api.run("owner.create_owner_history", self.file),
+                "RelatingProcess": self.settings["predecessor_task"],
+                "SequenceType": self.settings["sequence_type"],
+                "RelatedProcess": self.settings["task"],
+            })
+        return rel_sequence
\ No newline at end of file
diff --git a/src/ifcopenshell-python/ifcopenshell/api/sequence/assign_task_successor.py b/src/ifcopenshell-python/ifcopenshell/api/sequence/assign_task_successor.py
new file mode 100644
index 0000000000..21f818949f
--- /dev/null
+++ b/src/ifcopenshell-python/ifcopenshell/api/sequence/assign_task_successor.py
@@ -0,0 +1,25 @@
+import ifcopenshell
+import ifcopenshell.api
+
+
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {
+            "task": None,
+            "sequence_type":"FINISH_START",
+            "successor_task": None,
+        }
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        #TODO: tasks can only have one relationship between oneanother: if a relationship is already assigned, it should overide the previous one's settings.
+        rel_sequence = self.file.create_entity("IfcRelSequence",**{
+                "GlobalId": ifcopenshell.guid.new(),
+                "OwnerHistory": ifcopenshell.api.run("owner.create_owner_history", self.file),
+                "RelatingProcess": self.settings["task"],
+                "SequenceType": self.settings["sequence_type"],
+                "RelatedProcess": self.settings["successor_task"],
+            })
+        return rel_sequence
\ No newline at end of file