diff --git a/src/ewoksdraw/graph_to_svg.py b/src/ewoksdraw/graph_to_svg.py
index e91a3b6..bd49bc5 100644
--- a/src/ewoksdraw/graph_to_svg.py
+++ b/src/ewoksdraw/graph_to_svg.py
@@ -13,17 +13,32 @@
 from .svg.svg_canvas import SvgCanvas
 from .svg.svg_task import SvgTask
 from .svg.svg_task_group import SvgTaskGroup
+from .utils import get_edge_sources_and_targets
 
 
 def build_svg_task_group(graph: TaskGraph) -> SvgTaskGroup:
     """Build an SVG task group from an Ewoks task graph."""
+    source_outputs_per_node, target_inputs_per_node = get_edge_sources_and_targets(
+        graph
+    )
+
     svg_tasks = {}
     for node_id, node_attrs in graph.graph.nodes.items():
         signature = node_signature(node_id, node_attrs)
+
+        # Use dict instead of set to remove duplicate while keeping order
+        inputs = dict.fromkeys(node_input.name for node_input in signature.inputs)
+        # Add eventual missing target inputs
+        inputs.update(dict.fromkeys(target_inputs_per_node[node_id]))
+
+        outputs = dict.fromkeys(node_output.name for node_output in signature.outputs)
+        # Add eventual missing source outputs
+        outputs.update(dict.fromkeys(source_outputs_per_node[node_id]))
+
         svg_tasks[node_id] = SvgTask(
             task_name=node_id,
-            input_names=[node_input.name for node_input in signature.inputs],
-            output_names=[node_output.name for node_output in signature.outputs],
+            input_names=list(inputs.keys()),
+            output_names=list(outputs.keys()),
             import_error=bool(signature.import_error),
         )
     return SvgTaskGroup(
diff --git a/src/ewoksdraw/layout/elk_converter.py b/src/ewoksdraw/layout/elk_converter.py
index 78cf9db..4c4b2ca 100644
--- a/src/ewoksdraw/layout/elk_converter.py
+++ b/src/ewoksdraw/layout/elk_converter.py
@@ -1,6 +1,7 @@
-import warnings
 from typing import Any
 
+from ..utils import get_valid_data_mappings
+
 try:
     from typing import NotRequired
 except ImportError:
@@ -152,38 +153,19 @@ def convert_ewoks_to_elk_graph(
     used_ids.add(root_id)
 
     edges: list[ElkEdgeBeforeLayout] = []
-    for source, target, link_attrs in ewoks_graph.graph.edges(data=True):
-        if link_attrs.get("map_all_data", False):
-            warnings.warn(
-                f"Ewoks link {source!r} -> {target!r} uses 'map_all_data', which "
-                "is not yet supported.",
-                UserWarning,
-                stacklevel=2,
-            )
-
-        for mapping in link_attrs.get("data_mapping", []):
-            source_output = mapping.get("source_output")
-            if source_output is None:
-                warnings.warn(
-                    f"Data mapping on Ewoks link {source!r} -> {target!r} has no "
-                    "'source_output', which is not yet supported.",
-                    UserWarning,
-                    stacklevel=2,
-                )
-                continue
-
-            edge_id = _available_elk_id(
-                f"edge_{len(edges)}_{source}_{target}", used_ids
-            )
-
-            edges.append(
-                {
-                    "id": edge_id,
-                    "sources": [f"{source}.output.{source_output}"],
-                    "targets": [f"{target}.input.{mapping['target_input']}"],
-                }
-            )
-            used_ids.add(edge_id)
+    for mapping in get_valid_data_mappings(ewoks_graph):
+        edge_id = _available_elk_id(
+            f"edge_{len(edges)}_{mapping.source}_{mapping.target}", used_ids
+        )
+
+        edges.append(
+            {
+                "id": edge_id,
+                "sources": [f"{mapping.source}.output.{mapping.source_output}"],
+                "targets": [f"{mapping.target}.input.{mapping.target_input}"],
+            }
+        )
+        used_ids.add(edge_id)
 
     return {
         "id": root_id,
diff --git a/src/ewoksdraw/models.py b/src/ewoksdraw/models.py
new file mode 100644
index 0000000..9c2cd3d
--- /dev/null
+++ b/src/ewoksdraw/models.py
@@ -0,0 +1,8 @@
+from typing import NamedTuple
+
+
+class DataMapping(NamedTuple):
+    source: str
+    target: str
+    source_output: str
+    target_input: str
diff --git a/src/ewoksdraw/utils.py b/src/ewoksdraw/utils.py
new file mode 100644
index 0000000..8dbe678
--- /dev/null
+++ b/src/ewoksdraw/utils.py
@@ -0,0 +1,53 @@
+import warnings
+from collections import defaultdict
+
+from ewokscore.graph import TaskGraph
+
+from .models import DataMapping
+
+
+def get_valid_data_mappings(ewoks_graph: TaskGraph) -> list[DataMapping]:
+    data_mappings: list[DataMapping] = []
+    for source, target, link_attrs in ewoks_graph.graph.edges(data=True):
+        if link_attrs.get("map_all_data", False):
+            warnings.warn(
+                f"Ewoks link {source!r} -> {target!r} uses 'map_all_data', which "
+                "is not yet supported.",
+                UserWarning,
+                stacklevel=2,
+            )
+
+        for mapping in link_attrs.get("data_mapping", []):
+            source_output = mapping.get("source_output")
+            if source_output is None:
+                warnings.warn(
+                    f"Data mapping on Ewoks link {source!r} -> {target!r} has no "
+                    "'source_output', which is not yet supported.",
+                    UserWarning,
+                    stacklevel=2,
+                )
+                continue
+
+            data_mappings.append(
+                DataMapping(
+                    source=source,
+                    target=target,
+                    source_output=source_output,
+                    target_input=mapping["target_input"],
+                )
+            )
+
+    return data_mappings
+
+
+def get_edge_sources_and_targets(
+    graph: TaskGraph,
+) -> tuple[dict[str, list[str]], dict[str, list[str]]]:
+    data_mappings = get_valid_data_mappings(graph)
+    sources: dict[str, list[str]] = defaultdict(list[str])
+    targets: dict[str, list[str]] = defaultdict(list[str])
+    for mapping in data_mappings:
+        sources[mapping.source].append(mapping.source_output)
+        targets[mapping.target].append(mapping.target_input)
+
+    return sources, targets