eclipse-syson · AxelRICHARD · Feb 12, 2026 · Feb 11, 2026
diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
@@ -64,6 +64,7 @@ Integration tests that require Elasticsearch now need to extend `AbstractIntegra
 
 === New features
 
+- https://github.com/eclipse-syson/syson/issues/1977[#1977] [diagram] Display the _timeslice_ and _snapshot_ prefixes in the label of `OccurrenceUsage` graphical nodes and some of the graphical nodes representing subclasses of `OccurrenceUsage`.
 
 == v2026.1.0
 

diff --git a/...services/src/main/java/org/eclipse/syson/diagram/services/utils/MultiLineLabelSwitch.java b/...services/src/main/java/org/eclipse/syson/diagram/services/utils/MultiLineLabelSwitch.java
@@ -102,7 +102,7 @@ public String caseElement(Element object) {
     public String caseAcceptActionUsage(AcceptActionUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("accept action")
@@ -139,7 +139,7 @@ public String caseActionDefinition(ActionDefinition object) {
     public String caseActionUsage(ActionUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("action")
@@ -173,7 +173,7 @@ public String caseAllocationDefinition(AllocationDefinition object) {
     public String caseAllocationUsage(AllocationUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("allocation")
@@ -226,7 +226,7 @@ public String caseAttributeUsage(AttributeUsage object) {
     public String caseAssignmentActionUsage(AssignmentActionUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("assign")
@@ -254,7 +254,7 @@ public String caseCaseDefinition(CaseDefinition object) {
     public String caseCaseUsage(CaseUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("case")
@@ -311,7 +311,7 @@ public String caseConcernDefinition(ConcernDefinition object) {
     public String caseConcernUsage(ConcernUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("concern")
@@ -345,7 +345,7 @@ public String caseConstraintDefinition(ConstraintDefinition object) {
     public String caseConstraintUsage(ConstraintUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("constraint")
@@ -434,7 +434,7 @@ public String caseEnumerationDefinition(EnumerationDefinition object) {
     public String caseExhibitStateUsage(ExhibitStateUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(this.getIsParallel(object.isIsParallel()))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
@@ -469,7 +469,7 @@ public String caseInterfaceDefinition(InterfaceDefinition object) {
     public String caseInterfaceUsage(InterfaceUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("interface")
@@ -519,7 +519,7 @@ public String caseNamespaceImport(NamespaceImport object) {
     public String caseItemUsage(ItemUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("item")
@@ -568,8 +568,7 @@ public String caseOccurrenceDefinition(OccurrenceDefinition object) {
     public String caseOccurrenceUsage(OccurrenceUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
-                .append(this.individual(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("occurrence")
@@ -612,7 +611,7 @@ public String casePartUsage(PartUsage object) {
         if (!(object.getOwningMembership() instanceof ActorMembership)) {
             // The label shouldn't contain abstract, ref, or part if the part represents an actor.
             label
-                    .append(this.getBasicNamePrefix(object))
+                    .append(this.getOccurrenceUsagePrefix(object))
                     .append(LabelConstants.OPEN_QUOTE)
                     .append(this.reference(object))
                     .append("part")
@@ -634,7 +633,7 @@ public String casePartUsage(PartUsage object) {
     public String casePerformActionUsage(PerformActionUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append(this.getPerformActionUsageTag(object))
@@ -666,7 +665,7 @@ public String casePortDefinition(PortDefinition object) {
     public String casePortUsage(PortUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("port")
@@ -732,7 +731,7 @@ public String caseRequirementDefinition(RequirementDefinition object) {
     public String caseRequirementUsage(RequirementUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("requirement")
@@ -752,7 +751,7 @@ public String caseRequirementUsage(RequirementUsage object) {
     public String caseSatisfyRequirementUsage(SatisfyRequirementUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("satisfy requirement")
@@ -786,7 +785,7 @@ public String caseUseCaseDefinition(UseCaseDefinition object) {
     public String caseUseCaseUsage(UseCaseUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("use case")
@@ -821,7 +820,7 @@ public String caseStateDefinition(StateDefinition object) {
     public String caseStateUsage(StateUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(this.getIsParallel(object.isIsParallel()))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
@@ -842,7 +841,7 @@ public String caseStateUsage(StateUsage object) {
     public String caseViewUsage(ViewUsage object) {
         StringBuilder label = new StringBuilder();
         label
-                .append(this.getBasicNamePrefix(object))
+                .append(this.getOccurrenceUsagePrefix(object))
                 .append(LabelConstants.OPEN_QUOTE)
                 .append(this.reference(object))
                 .append("view")
@@ -871,6 +870,14 @@ private StringBuilder getIsParallel(boolean isParallel) {
         return parallel;
     }
 
+    private String getOccurrenceUsagePrefix(OccurrenceUsage occurrenceUsage) {
+        return new StringBuilder()
+                .append(this.getBasicNamePrefix(occurrenceUsage))
+                .append(this.individual(occurrenceUsage))
+                .append(this.portionKind(occurrenceUsage))
+                .toString();
+    }
+
     private String getBasicNamePrefix(Type object) {
         StringBuilder label = new StringBuilder();
         if (object instanceof Usage usage) {
@@ -1004,6 +1011,18 @@ private String individual(boolean isIndividual) {
         return label.toString();
     }
 
+    private String portionKind(OccurrenceUsage occurrenceUsage) {
+        StringBuilder label = new StringBuilder();
+        if (occurrenceUsage.isSetPortionKind()) {
+            label
+                    .append(LabelConstants.OPEN_QUOTE)
+                    .append(occurrenceUsage.getPortionKind().getName())
+                    .append(LabelConstants.CLOSE_QUOTE)
+                    .append(LabelConstants.CR);
+        }
+        return label.toString();
+    }
+
     private String assignmentActionUsageDetails(AssignmentActionUsage aau) {
         StringBuilder label = new StringBuilder();
         if (aau.getReferent() != null) {

diff --git a/...ices/src/test/java/org/eclipse/syson/diagram/services/utils/MultilineLabelSwitchTest.java b/...ices/src/test/java/org/eclipse/syson/diagram/services/utils/MultilineLabelSwitchTest.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2024, 2025 Obeo.
+ * Copyright (c) 2024, 2026 Obeo.
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
  * which accompanies this distribution, and is available at
@@ -26,6 +26,8 @@
 import org.eclipse.syson.sysml.Definition;
 import org.eclipse.syson.sysml.Element;
 import org.eclipse.syson.sysml.FeatureMembership;
+import org.eclipse.syson.sysml.OccurrenceUsage;
+import org.eclipse.syson.sysml.PortionKind;
 import org.eclipse.syson.sysml.SysmlFactory;
 import org.eclipse.syson.sysml.SysmlPackage;
 import org.eclipse.syson.sysml.Type;
@@ -63,6 +65,8 @@ public class MultilineLabelSwitchTest {
 
     private static final String DEFAULT_ASSIGNMENT_ACTION_USAGE_LABEL = LabelConstants.OPEN_QUOTE + REF_ATTRIBUTE_LABEL + "assign" + LabelConstants.CLOSE_QUOTE + LabelConstants.CR;
 
+    private static final String DEFAULT_CASE_USAGE_LABEL = LabelConstants.OPEN_QUOTE + REF_ATTRIBUTE_LABEL + "case" + LabelConstants.CLOSE_QUOTE + LabelConstants.CR;
+
     private static final String DEFAULT_COMMENT_LABEL = LabelConstants.OPEN_QUOTE + "comment" + LabelConstants.CLOSE_QUOTE + LabelConstants.CR;
 
     private static final String DEFAULT_CONCERN_DEFINITION_LABEL = LabelConstants.OPEN_QUOTE + "concern def" + LabelConstants.CLOSE_QUOTE + LabelConstants.CR;
@@ -113,6 +117,8 @@ public class MultilineLabelSwitchTest {
 
     private static final String DEFAULT_USE_CASE_USAGE_LABEL = LabelConstants.OPEN_QUOTE + REF_ATTRIBUTE_LABEL + "use case" + LabelConstants.CLOSE_QUOTE + LabelConstants.CR;
 
+    private static final String DEFAULT_VIEW_USAGE_LABEL = LabelConstants.OPEN_QUOTE + REF_ATTRIBUTE_LABEL + "view" + LabelConstants.CLOSE_QUOTE + LabelConstants.SPACE;
+
     private static final String DEFAULT_STATE_DEFINITION_LABEL = LabelConstants.OPEN_QUOTE + "state def" + LabelConstants.CLOSE_QUOTE + LabelConstants.CR;
 
     private static final String DEFAULT_STATE_USAGE_LABEL = LabelConstants.OPEN_QUOTE + REF_ATTRIBUTE_LABEL + "state" + LabelConstants.CLOSE_QUOTE + LabelConstants.CR;
@@ -203,6 +209,28 @@ private static Stream<Arguments> prefixParameterProvider() {
         );
     }
 
+    private static Stream<Arguments> timesliceSnapshotPrefixParameterProvider() {
+        return Stream.of(
+                Arguments.of(SYSML.getOccurrenceUsage(), DEFAULT_OCCURRENCE_USAGE_LABEL),
+                Arguments.of(SYSML.getActionUsage(), DEFAULT_ACTION_LABEL),
+                Arguments.of(SYSML.getAcceptActionUsage(), DEFAULT_ACCEPT_ACTION_LABEL),
+                Arguments.of(SYSML.getAssignmentActionUsage(), DEFAULT_ASSIGNMENT_ACTION_USAGE_LABEL),
+                Arguments.of(SYSML.getCaseUsage(), DEFAULT_CASE_USAGE_LABEL),
+                Arguments.of(SYSML.getUseCaseUsage(), DEFAULT_USE_CASE_USAGE_LABEL),
+                Arguments.of(SYSML.getPerformActionUsage(), DEFAULT_PERFORM_ACTION_USAGE_LABEL),
+                Arguments.of(SYSML.getExhibitStateUsage(), DEFAULT_EXHIBIT_STATE_USAGE_LABEL),
+                Arguments.of(SYSML.getStateUsage(), DEFAULT_STATE_USAGE_LABEL),
+                Arguments.of(SYSML.getConstraintUsage(), DEFAULT_CONSTRAINT_USAGE_LABEL),
+                Arguments.of(SYSML.getSatisfyRequirementUsage(), DEFAULT_SATISFY_REQUIREMENT_USAGE_LABEL),
+                Arguments.of(SYSML.getItemUsage(), DEFAULT_ITEM_USAGE_LABEL),
+                Arguments.of(SYSML.getPartUsage(), DEFAULT_PART_USAGE_LABEL),
+                Arguments.of(SYSML.getAllocationUsage(), DEFAULT_ALLOCATION_USAGE_LABEL),
+                Arguments.of(SYSML.getInterfaceUsage(), DEFAULT_INTERFACE_USAGE_LABEL),
+                Arguments.of(SYSML.getViewUsage(), DEFAULT_VIEW_USAGE_LABEL),
+                Arguments.of(SYSML.getPortUsage(), DEFAULT_PORT_USAGE_LABEL)
+        );
+    }
+
     @ParameterizedTest(name = "[{index}] Check default prefix in {0} element label")
     @MethodSource("defaultParameterProvider")
     public void testDefaultLabel(EClass elementType, String defaultLabel) {
@@ -294,6 +322,40 @@ public void testPrefixLabelWithVariantProperty(EClass elementType, String defaul
         }
     }
 
+    @ParameterizedTest(name = "[{index}] Check timeslice prefix in {0} element label")
+    @MethodSource("timesliceSnapshotPrefixParameterProvider")
+    public void testPrefixLabelWithTimesliceProperty(EClass elementType, String defaultLabel) {
+        Element element = (Element) SysmlFactory.eINSTANCE.create(elementType);
+        if (element instanceof OccurrenceUsage occurrenceUsage) {
+            occurrenceUsage.setPortionKind(PortionKind.TIMESLICE);
+            String timeslicePrefix = LabelConstants.OPEN_QUOTE + PortionKind.TIMESLICE.getName() + LabelConstants.CLOSE_QUOTE + LabelConstants.CR;
+            if (element instanceof AcceptActionUsage) {
+                assertEquals(timeslicePrefix + defaultLabel + LabelConstants.CR,
+                        this.multiLineLabelSwitch.doSwitch(element));
+            } else {
+                assertEquals(timeslicePrefix + defaultLabel,
+                        this.multiLineLabelSwitch.doSwitch(element));
+            }
+        }
+    }
+
+    @ParameterizedTest(name = "[{index}] Check snapshot prefix in {0} element label")
+    @MethodSource("timesliceSnapshotPrefixParameterProvider")
+    public void testPrefixLabelWithSnapshotProperty(EClass elementType, String defaultLabel) {
+        Element element = (Element) SysmlFactory.eINSTANCE.create(elementType);
+        if (element instanceof OccurrenceUsage occurrenceUsage) {
+            occurrenceUsage.setPortionKind(PortionKind.SNAPSHOT);
+            String snapshotPrefix = LabelConstants.OPEN_QUOTE + PortionKind.SNAPSHOT.getName() + LabelConstants.CLOSE_QUOTE + LabelConstants.CR;
+            if (element instanceof AcceptActionUsage) {
+                assertEquals(snapshotPrefix + defaultLabel + LabelConstants.CR,
+                        this.multiLineLabelSwitch.doSwitch(element));
+            } else {
+                assertEquals(snapshotPrefix + defaultLabel,
+                        this.multiLineLabelSwitch.doSwitch(element));
+            }
+        }
+    }
+
     private Element createNestedElementIn(Element parentElement, EClass elementType) {
         Element newElement = (Element) SysmlFactory.eINSTANCE.create(elementType);
         FeatureMembership membership = SysmlFactory.eINSTANCE.createFeatureMembership();

diff --git a/doc/content/modules/user-manual/pages/release-notes/2026.3.0.adoc b/doc/content/modules/user-manual/pages/release-notes/2026.3.0.adoc
@@ -71,6 +71,7 @@ part system {
 This tool allows to create a `SatisfyRequirementUsage` based on the `RequirementUsage` selected during the tool creation.
 ** Add _New Satisfy Requirement_ graphical edge tool between `Feature` graphical nodes and `RequirementUsage` graphical nodes.
 This tool allows to create a `SatisfyRequirementUsage` between the `Feature` and `RequirementUsage` selected during the tool creation.
+** Add the  _timeslice_ and _snapshot_ prefixes in the label of `OccurrenceUsage` graphical nodes and some of the graphical nodes representing subclasses of `OccurrenceUsage`.
 
 * In textual import/export:
Original file line number	Diff line number	Diff line change
Expand Up		@@ -64,6 +64,7 @@ Integration tests that require Elasticsearch now need to extend `AbstractIntegra

		=== New features

		- https://github.com/eclipse-syson/syson/issues/1977[#1977] [diagram] Display the _timeslice_ and _snapshot_ prefixes in the label of `OccurrenceUsage` graphical nodes and some of the graphical nodes representing subclasses of `OccurrenceUsage`.

		== v2026.1.0

Expand Down