diff --git a/SysML2.NET.Tests/Extend/BehaviorExtensionsTestFixture.cs b/SysML2.NET.Tests/Extend/BehaviorExtensionsTestFixture.cs
index b95e2d79..12eac816 100644
--- a/SysML2.NET.Tests/Extend/BehaviorExtensionsTestFixture.cs
+++ b/SysML2.NET.Tests/Extend/BehaviorExtensionsTestFixture.cs
@@ -1,7 +1,7 @@
 // -------------------------------------------------------------------------------------------------
 // <copyright file="BehaviorExtensionsTestFixture.cs" company="Starion Group S.A.">
 // 
-//   Copyright 2022-2026 Starion Group S.A.
+//   Copyright (C) 2022-2026 Starion Group S.A.
 // 
 //   Licensed under the Apache License, Version 2.0 (the "License");
 //   you may not use this file except in compliance with the License.
@@ -21,24 +21,64 @@
 namespace SysML2.NET.Tests.Extend
 {
     using System;
-    
+
     using NUnit.Framework;
-    
+
+    using SysML2.NET.Core.Core.Types;
+    using SysML2.NET.Core.POCO.Core.Features;
+    using SysML2.NET.Core.POCO.Core.Types;
     using SysML2.NET.Core.POCO.Kernel.Behaviors;
+    using SysML2.NET.Extensions;
 
     [TestFixture]
     public class BehaviorExtensionsTestFixture
     {
         [Test]
-        public void ComputeParameter_ThrowsNotSupportedException()
+        public void VerifyComputeParameter()
         {
-            Assert.That(() => ((IBehavior)null).ComputeParameter(), Throws.TypeOf<NotSupportedException>());
+            // Null subject:
+            Assert.That(() => ((IBehavior)null).ComputeParameter(), Throws.TypeOf<ArgumentNullException>());
+
+            // Empty Behavior Parameter list:
+            var emptySubject = new Behavior();
+            Assert.That(emptySubject.ComputeParameter(), Has.Count.EqualTo(0));
+
+            // Typed by DirectedFeature:
+            var subject = new Behavior();
+            var parameter = new Feature { Direction = FeatureDirectionKind.In };
+            var plainFeature = new Feature();
+            subject.AssignOwnership(new FeatureMembership(), parameter);
+            subject.AssignOwnership(new FeatureMembership(), plainFeature);
+
+            using (Assert.EnterMultipleScope())
+            {
+                Assert.That(subject.ComputeParameter(), Does.Contain(parameter));
+                Assert.That(subject.ComputeParameter(), Does.Not.Contain(plainFeature));
+            }
         }
-        
+
         [Test]
-        public void ComputeStep_ThrowsNotSupportedException()
+        public void VerifyComputeStep()
         {
-            Assert.That(() => ((IBehavior)null).ComputeStep(), Throws.TypeOf<NotSupportedException>());
+            // Null subject:
+            Assert.That(() => ((IBehavior)null).ComputeStep(), Throws.TypeOf<ArgumentNullException>());
+
+            // Empty Behavior Step list:
+            var emptySubject = new Behavior();
+            Assert.That(emptySubject.ComputeStep(), Has.Count.EqualTo(0));
+
+            // Typed by Step:
+            var subject = new Behavior();
+            var step = new Step();
+            var plainFeature = new Feature();
+            subject.AssignOwnership(new FeatureMembership(), step);
+            subject.AssignOwnership(new FeatureMembership(), plainFeature);
+
+            using (Assert.EnterMultipleScope())
+            {
+                Assert.That(subject.ComputeStep(), Does.Contain(step));
+                Assert.That(subject.ComputeStep(), Does.Not.Contain(plainFeature));
+            }
         }
     }
 }
diff --git a/SysML2.NET/Extend/BehaviorExtensions.cs b/SysML2.NET/Extend/BehaviorExtensions.cs
index 3a9f2531..89fa5968 100644
--- a/SysML2.NET/Extend/BehaviorExtensions.cs
+++ b/SysML2.NET/Extend/BehaviorExtensions.cs
@@ -1,20 +1,20 @@
 // -------------------------------------------------------------------------------------------------
 // <copyright file="BehaviorExtensions.cs" company="Starion Group S.A.">
-//
-//    Copyright (C) 2022-2026 Starion Group S.A.
-//
-//    Licensed under the Apache License, Version 2.0 (the "License");
-//    you may not use this file except in compliance with the License.
-//    You may obtain a copy of the License at
-//
+// 
+//   Copyright (C) 2022-2026 Starion Group S.A.
+// 
+//   Licensed under the Apache License, Version 2.0 (the "License");
+//   you may not use this file except in compliance with the License.
+//   You may obtain a copy of the License at
+// 
 //        http://www.apache.org/licenses/LICENSE-2.0
-//
+// 
 //    Unless required by applicable law or agreed to in writing, software
 //    distributed under the License is distributed on an "AS IS" BASIS,
 //    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 //    See the License for the specific language governing permissions and
 //    limitations under the License.
-//
+// 
 // </copyright>
 // ------------------------------------------------------------------------------------------------
 
@@ -22,20 +22,13 @@ namespace SysML2.NET.Core.POCO.Kernel.Behaviors
 {
     using System;
     using System.Collections.Generic;
+    using System.Linq;
 
-    using SysML2.NET.Core.Core.Types;
-    using SysML2.NET.Core.Root.Namespaces;
-    using SysML2.NET.Core.POCO.Core.Classifiers;
     using SysML2.NET.Core.POCO.Core.Features;
-    using SysML2.NET.Core.POCO.Core.Types;
-    using SysML2.NET.Core.POCO.Kernel.Classes;
-    using SysML2.NET.Core.POCO.Root.Annotations;
-    using SysML2.NET.Core.POCO.Root.Elements;
-    using SysML2.NET.Core.POCO.Root.Namespaces;
 
     /// <summary>
-    /// The <see cref="BehaviorExtensions"/> class provides extensions methods for
-    /// the <see cref="IBehavior"/> interface
+    /// The <see cref="BehaviorExtensions" /> class provides extensions methods for
+    /// the <see cref="IBehavior" /> interface
     /// </summary>
     internal static class BehaviorExtensions
     {
@@ -43,15 +36,16 @@ internal static class BehaviorExtensions
         /// Computes the derived property.
         /// </summary>
         /// <param name="behaviorSubject">
-        /// The subject <see cref="IBehavior"/>
+        /// The subject <see cref="IBehavior" />
         /// </param>
         /// <returns>
         /// the computed result
         /// </returns>
-        [System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
         internal static List<IFeature> ComputeParameter(this IBehavior behaviorSubject)
         {
-            throw new NotSupportedException("Create a GitHub issue when this method is required");
+            return behaviorSubject == null
+                ? throw new ArgumentNullException(nameof(behaviorSubject))
+                : [..behaviorSubject.feature.Where(memberFeature => behaviorSubject.DirectionOf(memberFeature) != null)];
         }
 
         /// <summary>
@@ -64,16 +58,16 @@ internal static List<IFeature> ComputeParameter(this IBehavior behaviorSubject)
         /// </code>
         /// </remarks>
         /// <param name="behaviorSubject">
-        /// The subject <see cref="IBehavior"/>
+        /// The subject <see cref="IBehavior" />
         /// </param>
         /// <returns>
         /// the computed result
         /// </returns>
-        [System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
         internal static List<IStep> ComputeStep(this IBehavior behaviorSubject)
         {
-            throw new NotSupportedException("Create a GitHub issue when this method is required");
+            return behaviorSubject == null
+                ? throw new ArgumentNullException(nameof(behaviorSubject))
+                : [..behaviorSubject.feature.OfType<IStep>()];
         }
-
     }
 }