diff --git a/capellambse_context_diagrams/collectors/default.py b/capellambse_context_diagrams/collectors/default.py
index 36b1c5e5..76f6c8dc 100644
--- a/capellambse_context_diagrams/collectors/default.py
+++ b/capellambse_context_diagrams/collectors/default.py
@@ -49,7 +49,7 @@ def __init__(
         self.global_boxes = {self.centerbox.id: self.centerbox}
         self.made_boxes = {self.centerbox.id: self.centerbox}
         self.boxes_to_delete = {self.centerbox.id}
-        self.edges: list[fa.AbstractExchange] = []
+        self.exchanges: list[fa.AbstractExchange] = []
         if self.diagram._display_parent_relation:
             self.diagram_target_owners = list(
                 generic.get_all_owners(self.diagram.target)
@@ -103,22 +103,56 @@ def process_context(self):
             generic.move_parent_boxes_to_owner(
                 owner_boxes, self.diagram.target, self.data
             )
-            generic.move_edges(owner_boxes, self.edges, self.data)
+            generic.move_edges(owner_boxes, self.exchanges, self.data)
 
         self.centerbox.height = max(
             self.centerbox.height, *stack_heights.values()
         )
 
+    def _process_port_spread(
+        self,
+        exs: list[fa.AbstractExchange],
+        attr: str,
+        inc: int,
+        port_spread: dict[str, int],
+        owners: dict[str, str],
+    ) -> None:
+        for ex in exs:
+            elem = getattr(ex, attr).owner
+            if (owner := owners.get(elem.uuid)) is None:
+                try:
+                    owner = [
+                        uuid
+                        for uuid in generic.get_all_owners(elem)
+                        if uuid not in self.diagram_target_owners
+                    ][-1]
+                except (IndexError, AttributeError):
+                    owner = elem.uuid
+                assert owner is not None
+                owners[elem.uuid] = owner
+            port_spread.setdefault(owner, 0)
+            port_spread[owner] += inc
+
     def _process_exchanges(self) -> tuple[
         list[common.GenericElement],
         list[generic.ExchangeData],
     ]:
-        ports = port_collector(self.diagram.target, self.diagram.type)
-        connections = port_exchange_collector(ports)
-        self.centerbox.ports = [makers.make_port(uuid) for uuid in connections]
-        self.edges = list(chain.from_iterable(connections.values()))
+        inc, out = port_collector(self.diagram.target, self.diagram.type)
+        inc_c = port_exchange_collector(inc)
+        out_c = port_exchange_collector(out)
+        inc_exchanges = list(chain.from_iterable(inc_c.values()))
+        out_exchanges = list(chain.from_iterable(out_c.values()))
+        port_spread: dict[str, int] = {}
+        owners: dict[str, str] = {}
+        self._process_port_spread(
+            inc_exchanges, "source", 1, port_spread, owners
+        )
+        self._process_port_spread(
+            out_exchanges, "target", -1, port_spread, owners
+        )
+        self.exchanges = inc_exchanges + out_exchanges
         ex_datas: list[generic.ExchangeData] = []
-        for ex in self.edges:
+        for ex in self.exchanges:
             if is_hierarchical := exchanges.is_hierarchical(
                 ex, self.centerbox
             ):
@@ -138,23 +172,39 @@ def _process_exchanges(self) -> tuple[
                     self.params,
                     is_hierarchical,
                 )
-                generic.exchange_data_collector(ex_data)
+                src, tgt = generic.exchange_data_collector(ex_data)
+                src_owner = owners.get(src.owner.uuid, "")
+                tgt_owner = owners.get(tgt.owner.uuid, "")
+                is_inc = tgt.parent == self.diagram.target
+                is_out = src.parent == self.diagram.target
+                if is_inc and is_out:
+                    pass
+                elif (is_out and (port_spread.get(tgt_owner, 0) > 0)) or (
+                    is_inc and (port_spread.get(src_owner, 0) <= 0)
+                ):
+                    elkdata.edges[-1].sources = [tgt.uuid]
+                    elkdata.edges[-1].targets = [src.uuid]
                 ex_datas.append(ex_data)
             except AttributeError:
                 continue
 
-        return ports, ex_datas
+        self.centerbox.ports = [
+            makers.make_port(uuid) for uuid in {**inc_c, **out_c}
+        ]
+        return (inc + out), ex_datas
 
     def _process_ports(self, stack_heights: dict[str, float | int]) -> None:
         ports, ex_datas = self._process_exchanges()
-        for port, local_ports, side in port_context_collector(ex_datas, ports):
-            _, label_height = helpers.get_text_extent(port.name)
+        for owner, local_ports, side in port_context_collector(
+            ex_datas, ports
+        ):
+            _, label_height = helpers.get_text_extent(owner.name)
             height = max(
                 label_height + 2 * makers.LABEL_VPAD,
                 makers.PORT_PADDING
                 + (makers.PORT_SIZE + makers.PORT_PADDING) * len(local_ports),
             )
-            if box := self.global_boxes.get(port.uuid):  # type: ignore[assignment]
+            if box := self.global_boxes.get(owner.uuid):  # type: ignore[assignment]
                 if box is self.centerbox:
                     continue
                 box.ports.extend(
@@ -163,14 +213,14 @@ def _process_ports(self, stack_heights: dict[str, float | int]) -> None:
                 box.height += height
             else:
                 box = self._make_box(
-                    port,
+                    owner,
                     height=height,
                     no_symbol=self.diagram._display_symbols_as_boxes,
                 )
                 box.ports = [makers.make_port(j.uuid) for j in local_ports]
 
             if self.diagram._display_parent_relation:
-                current = port
+                current = owner
                 while (
                     current
                     and current.uuid not in self.diagram_target_owners
@@ -236,38 +286,52 @@ def collector(
 
 def port_collector(
     target: common.GenericElement | common.ElementList, diagram_type: DT
-) -> list[common.GenericElement]:
+) -> tuple[list[common.GenericElement], list[common.GenericElement]]:
     """Savely collect ports from `target`."""
 
     def __collect(target):
-        all_ports: list[common.GenericElement] = []
+        incoming_ports: list[common.GenericElement] = []
+        outgoing_ports: list[common.GenericElement] = []
         for attr in generic.DIAGRAM_TYPE_TO_CONNECTOR_NAMES[diagram_type]:
             try:
                 ports = getattr(target, attr)
-                if ports and isinstance(
+                if not ports or not isinstance(
                     ports[0],
                     (fa.FunctionPort, fa.ComponentPort, cs.PhysicalPort),
                 ):
-                    all_ports.extend(ports)
+                    continue
+                if attr == "inputs":
+                    incoming_ports.extend(ports)
+                elif attr == "ports":
+                    for port in ports:
+                        if port.direction == "IN":
+                            incoming_ports.append(port)
+                        else:
+                            outgoing_ports.append(port)
+                else:
+                    outgoing_ports.extend(ports)
             except AttributeError:
                 pass
-        return all_ports
+        return incoming_ports, outgoing_ports
 
     if isinstance(target, cabc.Iterable):
         assert not isinstance(target, common.GenericElement)
-        all_ports: list[common.GenericElement] = []
+        incoming_ports: list[common.GenericElement] = []
+        outgoing_ports: list[common.GenericElement] = []
         for obj in target:
-            all_ports.extend(__collect(obj))
+            inc, out = __collect(obj)
+            incoming_ports.extend(inc)
+            outgoing_ports.extend(out)
     else:
-        all_ports = __collect(target)
-    return all_ports
+        incoming_ports, outgoing_ports = __collect(target)
+    return incoming_ports, outgoing_ports
 
 
 def _extract_edges(
-    obj: common.ElementList[common.GenericElement],
+    obj: common.GenericElement,
     attribute: str,
     filter: Filter,
-) -> common.ElementList[common.GenericElement] | list:
+) -> cabc.Iterable[common.GenericElement]:
     return filter(getattr(obj, attribute, []))
 
 
@@ -370,7 +434,8 @@ def derive_from_functions(
     assert isinstance(diagram.target, cs.Component)
     ports = []
     for fnc in diagram.target.allocated_functions:
-        ports.extend(port_collector(fnc, diagram.type))
+        inc, out = port_collector(fnc, diagram.type)
+        ports.extend(inc + out)
 
     context_box_ids = {child.id for child in data.children}
     components: dict[str, cs.Component] = {}
diff --git a/capellambse_context_diagrams/collectors/exchanges.py b/capellambse_context_diagrams/collectors/exchanges.py
index 16798403..a7baae83 100644
--- a/capellambse_context_diagrams/collectors/exchanges.py
+++ b/capellambse_context_diagrams/collectors/exchanges.py
@@ -22,7 +22,7 @@
 class ExchangeCollector(metaclass=abc.ABCMeta):
     """Base class for context collection on Exchanges."""
 
-    intermap: dict[str, DT] = {
+    intermap: dict[DT, tuple[str, str, str, str]] = {
         DT.OAB: ("source", "target", "allocated_interactions", "activities"),
         DT.SAB: (
             "source.owner",
@@ -216,9 +216,9 @@ def make_all_owners(
         obj: fa.AbstractFunction | fa.FunctionPort,
         boxes: dict[str, _elkjs.ELKInputChild],
     ) -> str:
-        owners: list[fa.AbstractFunction | cs.Component] = []
+        owners: list[common.GenericElement] = []
         assert self.right is not None and self.left is not None
-        root: cs.Component | None = None
+        root: _elkjs.ELKInputChild | None = None
         for uuid in generic.get_all_owners(obj):
             element = self.obj._model.by_uuid(uuid)
             if uuid in {self.right.id, self.left.id}:
@@ -230,7 +230,7 @@ def make_all_owners(
         if root is None:
             raise ValueError(f"No root found for {obj._short_repr_()}")
 
-        owner_box: common.GenericElement = root
+        owner_box = root
         for owner in reversed(owners):
             if isinstance(owner, fa.FunctionPort):
                 if owner.uuid in (p.id for p in owner_box.ports):
diff --git a/capellambse_context_diagrams/collectors/generic.py b/capellambse_context_diagrams/collectors/generic.py
index 41927d9e..94c8e6ea 100644
--- a/capellambse_context_diagrams/collectors/generic.py
+++ b/capellambse_context_diagrams/collectors/generic.py
@@ -254,7 +254,7 @@ def move_edges(
 
 def get_all_owners(obj: common.GenericElement) -> cabc.Iterator[str]:
     """Return the UUIDs from all owners of ``obj``."""
-    current = obj
+    current: common.GenericElement | None = obj
     while current is not None:
         yield current.uuid
         current = getattr(current, "owner", None)
diff --git a/capellambse_context_diagrams/collectors/tree_view.py b/capellambse_context_diagrams/collectors/tree_view.py
index fdd58d55..be396189 100644
--- a/capellambse_context_diagrams/collectors/tree_view.py
+++ b/capellambse_context_diagrams/collectors/tree_view.py
@@ -10,6 +10,7 @@
 import math
 import typing as t
 
+from capellambse.model import common
 from capellambse.model.crosslayer import information
 
 from .. import _elkjs, context
@@ -26,7 +27,6 @@
     "elk.direction": "DOWN",
     "edgeRouting": "ORTHOGONAL",
 }
-ASSOC_STYLECLASS = "__Association"
 
 
 class ClassProcessor:
@@ -41,7 +41,6 @@ def __init__(
         self.data_types: set[str] = set()
         self.legend_boxes: list[_elkjs.ELKInputChild] = []
         self.all_associations = all_associations
-        self.edge_counter = 0
 
     def __contains__(self, uuid: str) -> bool:
         objects = self.data.children + self.data.edges  # type: ignore[operator]
@@ -55,16 +54,12 @@ def process_class(self, cls: ClassInfo, params: dict[str, t.Any]):
             edges = [
                 assoc
                 for assoc in self.all_associations
-                if cls.prop in assoc.navigable_members
+                if cls.prop in list(assoc.navigable_members)
             ]
-            if len(edges) == 1:
-                edge_id = edges[0].uuid
-            else:
-                edge_id = f"{ASSOC_STYLECLASS}:{self.edge_counter}"
-                self.edge_counter += 1
+            edge_id = edges[0].uuid
             if edge_id not in self.made_edges:
                 self.made_edges.add(edge_id)
-                text = cls.prop.name
+                text = cls.prop.name if cls.prop else ""
                 if cls.multiplicity is None:
                     start = end = "1"
                 else:
@@ -183,7 +178,7 @@ class ClassInfo:
 
     source: information.Class
     target: information.Class | None
-    prop: information.Property
+    prop: information.Property | None
     partition: int
     multiplicity: tuple[str, str] | None
     generalizes: information.Class | None = None
@@ -266,7 +261,10 @@ def get_all_classes(
         process_property(property)
 
     if super == "ALL" or (super == "ROOT" and partition == 1):
-        if root.super and not root.super.is_primitive:
+        if (
+            isinstance(root.super, information.Class)
+            and not root.super.is_primitive
+        ):
             for prop in root.super.owned_properties:
                 process_property(
                     _PropertyInfo(
@@ -421,7 +419,7 @@ def _get_property_text(prop: information.Property) -> str:
 
 
 def _get_legend_labels(
-    obj: information.datatype.Enumeration | information.Class,
+    obj: common.GenericElement,
 ) -> cabc.Iterator[makers._LabelBuilder]:
     yield {
         "text": obj.name,
@@ -438,7 +436,7 @@ def _get_legend_labels(
     elif isinstance(obj, information.Class):
         labels = [_get_property_text(prop) for prop in obj.owned_properties]
     else:
-        return
+        labels = []
     layout_options = DATA_TYPE_LABEL_LAYOUT_OPTIONS
     for label in labels:
         yield {"text": label, "icon": (0, 0), "layout_options": layout_options}