diff --git a/.vscode/settings.json b/.vscode/settings.json
index 465eaa96..c571fc5d 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -30,6 +30,7 @@
         "Qualifiable",
         "rechtlich",
         "selbstaendige",
+        "Sematics",
         "submodel",
         "tsoa",
         "tsyringe",
diff --git a/angular.json b/angular.json
index ed1dac11..5d035353 100644
--- a/angular.json
+++ b/angular.json
@@ -36,10 +36,7 @@
                             "node_modules/bootstrap-icons/font/bootstrap-icons.min.css",
                             "projects/aas-portal/src/styles.scss"
                         ],
-                        "scripts": [],
-                        "allowedCommonJsDependencies": [
-                            "lodash-es"
-                        ]
+                        "scripts": []
                     },
                     "configurations": {
                         "production": {
diff --git a/package.json b/package.json
index 9682308c..c687d148 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
     "name": "aas-portal-project",
-    "version": "3.0.0-development.69",
+    "version": "3.0.0-development.70",
     "description": "Web-based visualization and control of asset administration shells.",
     "type": "module",
     "scripts": {
diff --git a/projects/aas-core/src/lib/index.ts b/projects/aas-core/src/lib/index.ts
index f93c38b2..8f50448f 100644
--- a/projects/aas-core/src/lib/index.ts
+++ b/projects/aas-core/src/lib/index.ts
@@ -13,10 +13,12 @@ import {
     Blob,
     Entity,
     Environment,
+    HasSemantics,
     Identifiable,
     MultiLanguageProperty,
     Property,
     Referable,
+    Reference,
     ReferenceElement,
     RelationshipElement,
     Submodel,
@@ -121,6 +123,35 @@ export function equalArray<T>(a: T[], b: T[]): boolean {
     return a.every((_, i) => a[i] === b[i]);
 }
 
+/**
+ * Determines whether the specified value is of type `HasSemantics`.
+ * @param value The current value.
+ * @returns `true` if the specified value is of type `HasSemantics`; otherwise, `false`.
+ */
+export function isReference(value: unknown): value is Reference {
+    if (!value || typeof value !== 'object') {
+        return false;
+    }
+
+    return typeof (value as Reference).type === 'string' && Array.isArray((value as Reference).keys);
+}
+
+/**
+ * Determines whether the specified value is of type `HasSemantics`.
+ * @param value The current value.
+ * @returns `true` if the specified value is of type `HasSemantics`; otherwise, `false`.
+ */
+export function isHasSemantics(value: unknown): value is HasSemantics {
+    if (!value || typeof value !== 'object') {
+        return false;
+    }
+
+    return (
+        isReference((value as HasSemantics).semanticId) ||
+        Array.isArray((value as HasSemantics).supplementalSemanticIds)
+    );
+}
+
 /**
  * Determines whether the specified value represents a submodel element.
  * @param value The current value.
diff --git a/projects/aas-core/src/test/index.spec.ts b/projects/aas-core/src/test/index.spec.ts
index d94d73f6..1761b911 100644
--- a/projects/aas-core/src/test/index.spec.ts
+++ b/projects/aas-core/src/test/index.spec.ts
@@ -15,8 +15,10 @@ import {
     getEndpointType,
     isAssetAdministrationShell,
     isBlob,
+    isHasSemantics,
     isMultiLanguageProperty,
     isProperty,
+    isReference,
     isReferenceElement,
     isSubmodel,
     isSubmodelElement,
@@ -27,6 +29,7 @@ import {
     isValidPassword,
     stringFormat,
 } from '../lib/index.js';
+import { HasSemantics, Reference } from '../lib/aas.js';
 
 describe('index', () => {
     describe('isSubmodelElement', () => {
@@ -355,4 +358,52 @@ describe('index', () => {
             expect(getEndpointType('file:///endpoints/samples')).toEqual('FileSystem');
         });
     });
+
+    describe('isReference', () => {
+        it('indicates that value is of type reference', () => {
+            const value: Reference = {
+                keys: [],
+                type: 'ExternalReference',
+            };
+
+            expect(isReference(value)).toBeTruthy();
+        });
+
+        it('indicates that "{}" is not of type Reference', () => {
+            expect(isReference({})).toBeFalsy();
+        });
+
+        it('indicates that "undefined" is not of type Reference', () => {
+            expect(isReference(undefined)).toBeFalsy();
+        });
+
+        it('indicates that "null" is not of type Reference', () => {
+            expect(isReference(null)).toBeFalsy();
+        });
+    });
+
+    describe('isHasSemantics', () => {
+        it('indicates that value is of type HasSemantics', () => {
+            const value: HasSemantics = {
+                semanticId: {
+                    keys: [],
+                    type: 'ExternalReference',
+                },
+            };
+
+            expect(isHasSemantics(value)).toBeTruthy();
+        });
+
+        it('indicates that "{}" is not of type HasSemantics', () => {
+            expect(isHasSemantics({})).toBeFalsy();
+        });
+
+        it('indicates that "undefined" is not of type HasSemantics', () => {
+            expect(isHasSemantics(undefined)).toBeFalsy();
+        });
+
+        it('indicates that "null" is not of type HasSemantics', () => {
+            expect(isHasSemantics(null)).toBeFalsy();
+        });
+    });
 });
diff --git a/projects/aas-lib/src/lib/aas-tree/aas-tree-row.ts b/projects/aas-lib/src/lib/aas-tree/aas-tree-row.ts
index 712d68a4..f9ca036e 100644
--- a/projects/aas-lib/src/lib/aas-tree/aas-tree-row.ts
+++ b/projects/aas-lib/src/lib/aas-tree/aas-tree-row.ts
@@ -13,11 +13,13 @@ import {
     convertToString,
     getAbbreviation,
     getLocaleValue,
+    isAssetAdministrationShell,
     isBooleanType,
+    isHasSemantics,
     isIdentifiable,
-    isProperty,
-    isReferenceElement,
+    isMultiLanguageProperty,
     isSubmodel,
+    isSubmodelElement,
     mimeTypeToExtension,
     selectReferable,
     toBoolean,
@@ -135,18 +137,11 @@ class TreeInitialize {
             case 'Submodel':
             case 'SubmodelElementCollection':
             case 'SubmodelElementList':
+            case 'AnnotatedRelationshipElement':
+            case 'Entity':
+            case 'Operation':
                 isLeaf = false;
                 break;
-            case 'AnnotatedRelationshipElement': {
-                const relationship = element as aas.AnnotatedRelationshipElement;
-                isLeaf = !relationship.annotations || relationship.annotations.length === 0;
-                break;
-            }
-            case 'Entity': {
-                const entity = element as aas.Entity;
-                isLeaf = !entity.statements || entity.statements.length === 0;
-                break;
-            }
         }
 
         return new AASTreeRow(
@@ -212,6 +207,23 @@ class TreeInitialize {
                 return (referable as aas.SubmodelElementCollection).value ?? [];
             case 'SubmodelElementList':
                 return (referable as aas.SubmodelElementList).value ?? [];
+            case 'Operation': {
+                const operation = referable as aas.Operation;
+                const children: aas.Referable[] = [];
+                if (operation.inputVariables) {
+                    children.push(...operation.inputVariables.filter(variable => isSubmodelElement(variable)));
+                }
+
+                if (operation.inoutputVariables) {
+                    children.push(...operation.inoutputVariables.filter(variable => isSubmodelElement(variable)));
+                }
+
+                if (operation.outputVariables) {
+                    children.push(...operation.outputVariables.filter(variable => isSubmodelElement(variable)));
+                }
+
+                return children;
+            }
             default:
                 return [];
         }
@@ -246,46 +258,41 @@ class TreeInitialize {
     }
 
     private getValue(referable: aas.Referable | null, localeId: string): boolean | string | undefined {
-        if (referable) {
-            switch (referable.modelType) {
-                case 'Blob': {
-                    const blob = referable as aas.Blob;
-                    const extension = mimeTypeToExtension(blob.contentType);
-                    return blob.contentType ? `${blob.idShort}${extension}` : this.getSemanticId(blob);
-                }
-                case 'Entity':
-                    return (referable as aas.Entity).globalAssetId ?? '-';
-                case 'File': {
-                    const file = referable as aas.File;
-                    return file.value ? basename(normalize(file.value)) : '-';
-                }
-                case 'MultiLanguageProperty':
-                    return getLocaleValue((referable as aas.MultiLanguageProperty).value, localeId) ?? '-';
-                case 'Operation':
-                    return `${referable.idShort}()`;
-                case 'Property':
-                    return this.getPropertyValue(referable as aas.Property, localeId);
-                case 'Range': {
-                    const range = referable as aas.Range;
-                    return `${convertToString(range.min, localeId)} ... ${convertToString(range.max, localeId)}`;
-                }
-                case 'ReferenceElement':
-                    return (referable as aas.ReferenceElement).value?.keys.map(item => item.value).join('/');
-                default:
-                    return '-';
-            }
+        if (!referable) {
+            return '';
         }
 
-        return '';
-    }
-
-    private getSemanticId(hasSemantics: aas.HasSemantics): string {
-        const keys = hasSemantics.semanticId?.keys;
-        if (keys && keys.length > 0) {
-            return keys[0].value;
+        switch (referable.modelType) {
+            case 'Blob': {
+                const blob = referable as aas.Blob;
+                const extension = mimeTypeToExtension(blob.contentType);
+                return `${blob.idShort}${extension}`;
+            }
+            case 'Entity':
+                return (referable as aas.Entity).globalAssetId ?? '-';
+            case 'File': {
+                const file = referable as aas.File;
+                return file.value ? basename(normalize(file.value)) : '-';
+            }
+            case 'MultiLanguageProperty':
+                return getLocaleValue((referable as aas.MultiLanguageProperty).value, localeId) ?? '-';
+            case 'Operation':
+                return `${referable.idShort}()`;
+            case 'Property':
+                return this.getPropertyValue(referable as aas.Property, localeId);
+            case 'Range': {
+                const range = referable as aas.Range;
+                return `${convertToString(range.min, localeId)} ... ${convertToString(range.max, localeId)}`;
+            }
+            case 'ReferenceElement':
+                return this.referenceToString((referable as aas.ReferenceElement).value);
+            case 'SubmodelElementCollection':
+                return (referable as aas.SubmodelElementCollection).value?.length.toString() ?? '0';
+            case 'SubmodelElementList':
+                return (referable as aas.SubmodelElementList).value?.length.toString() ?? '0';
+            default:
+                return '';
         }
-
-        return '-';
     }
 
     private hasChildren(referable: aas.Referable): boolean {
@@ -314,6 +321,22 @@ class TreeInitialize {
                 const relationship = referable as aas.AnnotatedRelationshipElement;
                 return relationship.annotations != null && relationship.annotations.length > 0;
             }
+            case 'Operation': {
+                const operation = referable as aas.Operation;
+                if (operation.inputVariables) {
+                    return operation.inputVariables.some(variable => isSubmodelElement(variable.value));
+                }
+
+                if (operation.inoutputVariables) {
+                    return operation.inoutputVariables.some(variable => isSubmodelElement(variable.value));
+                }
+
+                if (operation.outputVariables) {
+                    return operation.outputVariables.some(variable => isSubmodelElement(variable.value));
+                }
+
+                return false;
+            }
             default:
                 return false;
         }
@@ -328,102 +351,75 @@ class TreeInitialize {
     }
 
     private getTypeInfo(referable: aas.Referable | null): string {
-        let value: string;
-        if (referable) {
-            switch (referable.modelType) {
-                case 'AnnotatedRelationshipElement':
-                    value = (referable as aas.AnnotatedRelationshipElement).annotations?.length.toString() ?? '-';
-                    break;
-                case 'AssetAdministrationShell':
-                    value = (referable as aas.Submodel).id;
-                    break;
-                case 'Blob':
-                    value = (referable as aas.Blob).contentType;
-                    break;
-                case 'File':
-                    value = (referable as aas.File).contentType;
-                    break;
-                case 'Property':
-                    value = (referable as aas.Property).valueType;
-                    break;
-                case 'Range':
-                    value = (referable as aas.Range).valueType;
-                    break;
-                case 'ReferenceElement':
-                    {
-                        const keys = (referable as aas.ReferenceElement).value?.keys;
-                        value = keys && keys.length > 0 ? keys[0].type : '-';
-                    }
-                    break;
-                case 'Submodel':
-                    value = `Semantic ID: ${this.referenceToString((referable as aas.Submodel).semanticId)}`;
-                    break;
-                case 'SubmodelElementCollection':
-                    value = (referable as aas.SubmodelElementCollection).value?.length.toString() ?? '0';
-                    break;
-                case 'SubmodelElementList':
-                    value = (referable as aas.SubmodelElementList).value?.length.toString() ?? '0';
-                    break;
-                case 'MultiLanguageProperty':
-                    {
-                        const mlp = referable as aas.MultiLanguageProperty;
-                        value = '';
-                        if (mlp && Array.isArray(mlp.value)) {
-                            value += `${mlp.value.map(item => item.language).join(', ')}`;
-                        }
-                    }
-                    break;
-                case 'Entity':
-                    {
-                        const entity = referable as aas.Entity;
-                        value = entity.entityType;
-                    }
-                    break;
-                case 'Operation':
-                    {
-                        const operation = referable as aas.Operation;
-                        value = '';
-                        if (operation.inputVariables && operation.inputVariables.length > 0) {
-                            value +=
-                                '(' +
-                                operation.inputVariables.map(v => this.variableToString(v.value)).join(', ') +
-                                ')';
-                        }
+        if (!referable) {
+            return '-';
+        }
 
-                        if (operation.outputVariables && operation.outputVariables.length === 1) {
-                            value += `: ${this.variableToString(operation.outputVariables[0].value)}`;
-                        } else if (operation.outputVariables && operation.outputVariables.length > 1) {
-                            value +=
-                                ': {' +
-                                operation.outputVariables.map(v => this.variableToString(v.value)).join(', ') +
-                                '}';
-                        }
-                    }
-                    break;
-                default:
-                    value = '-';
-                    break;
-            }
-        } else {
-            value = '-';
+        if (isAssetAdministrationShell(referable)) {
+            return referable.id;
         }
 
-        return value;
-    }
+        if (isMultiLanguageProperty(referable)) {
+            let value = '';
+            if (referable && Array.isArray(referable.value)) {
+                value += `${referable.value.map(item => item.language).join(', ')}`;
+            }
 
-    private variableToString(value: aas.SubmodelElement): string {
-        if (isProperty(value)) {
-            return `${value.idShort}: ${value.valueType}`;
+            return value;
         }
 
-        if (isReferenceElement(value)) {
-            return `${value.idShort}: ${value?.value?.keys.map(key => key.value).join('/')}`;
+        let value = '';
+        if (isHasSemantics(referable)) {
+            const a = this.getSemanticId(referable);
+            value = `Semantic ID: ${a}`;
+        }
+
+        switch (referable.modelType) {
+            case 'AnnotatedRelationshipElement':
+                value = (referable as aas.AnnotatedRelationshipElement).annotations?.length.toString() ?? '-';
+                break;
+            case 'Blob': {
+                const contentType = (referable as aas.Blob).contentType;
+                if (contentType) {
+                    value += ', ' + contentType;
+                }
+
+                break;
+            }
+            case 'File': {
+                const contentType = (referable as aas.File).contentType;
+                if (contentType) {
+                    value += ', ' + contentType;
+                }
+
+                break;
+            }
+            case 'Property': {
+                const valueType = (referable as aas.Property).valueType;
+                if (valueType) {
+                    value += ', ' + (valueType.startsWith('xs:') ? valueType.substring(3) : valueType);
+                }
+
+                break;
+            }
+            case 'Range': {
+                const valueType = (referable as aas.Range).valueType;
+                if (valueType) {
+                    value += ', ' + (valueType.startsWith('xs:') ? valueType.substring(3) : valueType);
+                }
+
+                break;
+            }
         }
 
-        return `${value.idShort}: ${value.modelType}`;
+        return value;
+    }
+
+    private getSemanticId(hasSematics: aas.HasSemantics): string {
+        return this.referenceToString(hasSematics?.semanticId);
     }
 
-    private referenceToString(reference?: aas.Reference): string {
+    private referenceToString(reference: aas.Reference | undefined): string {
         return reference?.keys.map(key => key.value).join('/') ?? '-';
     }
 }
diff --git a/projects/aas-lib/src/lib/aas-tree/aas-tree-search.ts b/projects/aas-lib/src/lib/aas-tree/aas-tree-search.ts
index 88ea191f..840c4c13 100644
--- a/projects/aas-lib/src/lib/aas-tree/aas-tree-search.ts
+++ b/projects/aas-lib/src/lib/aas-tree/aas-tree-search.ts
@@ -21,7 +21,7 @@ import {
 
 import { normalize } from '../convert';
 import { AASTreeRow } from './aas-tree-row';
-import { AASTreeStore, Operator, SearchQuery, SearchTerm } from './aas-tree.store';
+import { AASTreeService, Operator, SearchQuery, SearchTerm } from './aas-tree.service';
 
 @Injectable()
 export class AASTreeSearch {
@@ -29,7 +29,7 @@ export class AASTreeSearch {
     private terms: SearchTerm[] = [];
 
     public constructor(
-        private readonly store: AASTreeStore,
+        private readonly store: AASTreeService,
         private readonly translate: TranslateService,
     ) {}
 
@@ -337,7 +337,7 @@ export class AASTreeSearch {
                     return typeof min === 'number' && typeof max === 'number' && a >= min && a <= max;
                 } else {
                     const d = isDate
-                        ? parseDate(b, this.translate.currentLang)?.getTime() ?? 0
+                        ? (parseDate(b, this.translate.currentLang)?.getTime() ?? 0)
                         : parseNumber(b, this.translate.currentLang);
 
                     if (typeof d !== 'number') {
diff --git a/projects/aas-lib/src/lib/aas-tree/aas-tree.component.ts b/projects/aas-lib/src/lib/aas-tree/aas-tree.component.ts
index 068752eb..1960de57 100644
--- a/projects/aas-lib/src/lib/aas-tree/aas-tree.component.ts
+++ b/projects/aas-lib/src/lib/aas-tree/aas-tree.component.ts
@@ -50,7 +50,7 @@ import {
 } from '../submodel-template/submodel-template';
 
 import { AASTreeApiService } from './aas-tree-api.service';
-import { AASTreeStore } from './aas-tree.store';
+import { AASTreeService } from './aas-tree.service';
 
 interface PropertyValue {
     property: aas.Property;
@@ -63,7 +63,7 @@ interface PropertyValue {
     styleUrls: ['./aas-tree.component.scss'],
     standalone: true,
     imports: [NgClass, NgStyle, TranslateModule],
-    providers: [AASTreeSearch, AASTreeStore],
+    providers: [AASTreeSearch, AASTreeService],
     changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class AASTreeComponent implements OnInit, OnDestroy {
@@ -76,7 +76,7 @@ export class AASTreeComponent implements OnInit, OnDestroy {
     private webSocketSubject?: WebSocketSubject<WebSocketData>;
 
     public constructor(
-        private readonly store: AASTreeStore,
+        private readonly store: AASTreeService,
         private readonly router: Router,
         private readonly api: AASTreeApiService,
         private readonly searching: AASTreeSearch,
diff --git a/projects/aas-lib/src/lib/aas-tree/aas-tree.store.ts b/projects/aas-lib/src/lib/aas-tree/aas-tree.service.ts
similarity index 99%
rename from projects/aas-lib/src/lib/aas-tree/aas-tree.store.ts
rename to projects/aas-lib/src/lib/aas-tree/aas-tree.service.ts
index 039f443c..fac36460 100644
--- a/projects/aas-lib/src/lib/aas-tree/aas-tree.store.ts
+++ b/projects/aas-lib/src/lib/aas-tree/aas-tree.service.ts
@@ -33,7 +33,7 @@ interface AASTreeState {
 }
 
 @Injectable()
-export class AASTreeStore {
+export class AASTreeService {
     private readonly _state = signal<AASTreeState>({ matchIndex: -1, rows: [], nodes: [] });
 
     public constructor(
diff --git a/projects/aas-lib/src/test/aas-tree/aas-tree-search.spec.ts b/projects/aas-lib/src/test/aas-tree/aas-tree-search.spec.ts
index 2115de67..8ac80a1e 100644
--- a/projects/aas-lib/src/test/aas-tree/aas-tree-search.spec.ts
+++ b/projects/aas-lib/src/test/aas-tree/aas-tree-search.spec.ts
@@ -10,12 +10,12 @@ import { TestBed } from '@angular/core/testing';
 import { TranslateFakeLoader, TranslateLoader, TranslateModule, TranslateService } from '@ngx-translate/core';
 import { AASTreeSearch } from '../../lib/aas-tree/aas-tree-search';
 import { sampleDocument } from '../assets/sample-document';
-import { AASTreeStore } from '../../lib/aas-tree/aas-tree.store';
+import { AASTreeService } from '../../lib/aas-tree/aas-tree.store';
 import { NotifyService } from 'projects/aas-lib/dist';
 
 describe('AASTreeSearch', function () {
     let search: AASTreeSearch;
-    let store: AASTreeStore;
+    let store: AASTreeService;
 
     beforeEach(async function () {
         await TestBed.configureTestingModule({
@@ -25,7 +25,7 @@ describe('AASTreeSearch', function () {
                     provide: NotifyService,
                     useValue: jasmine.createSpyObj<NotifyService>(['error']),
                 },
-                AASTreeStore,
+                AASTreeService,
             ],
             imports: [
                 TranslateModule.forRoot({
@@ -37,7 +37,7 @@ describe('AASTreeSearch', function () {
             ],
         });
 
-        store = TestBed.inject(AASTreeStore);
+        store = TestBed.inject(AASTreeService);
         search = new AASTreeSearch(store, TestBed.inject(TranslateService));
         store.updateRows(sampleDocument);
     });