diff --git a/test/data/msmi/CraneController_OspModelDescription.xml b/test/data/msmi/CraneController_OspModelDescription.xml
index fe345063e..36dada791 100644
--- a/test/data/msmi/CraneController_OspModelDescription.xml
+++ b/test/data/msmi/CraneController_OspModelDescription.xml
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<OspModelDescription xmlns="http://opensimulationplatform.com/MSMI/OSPModelDescription">
+<OspModelDescription xmlns="http://opensimulationplatform.com/MSMI/OSPModelDescription"
+                     version="0.1">
     <UnitDefinitions>
         <Unit name="force~N">
             <BaseUnit kg="1" m="1" s="-2" A="0" K="0" mol="0" cd="0" rad="0" factor="1.0" offset="0.0"/>
@@ -9,7 +10,7 @@
         </Unit>
     </UnitDefinitions>
     <VariableGroups>
-        <VariableGroup type="flow" name="velocity">
+        <VariableGroup type="linear_velocity" name="velocity">
             <Variable name="p_Crane.f[1]" unit="velocity~m_s"/>
             <Variable name="p_Crane.f[2]" unit="velocity~m_s"/>
             <Variable name="p_Crane.f[3]" unit="velocity~m_s"/>
@@ -19,7 +20,7 @@
             <Variable name="Act_Limits[2]"/>
             <Variable name="Act_Limits[3]"/>
         </VariableGroup>
-        <VariableGroup type="effort" name="force">
+        <VariableGroup type="force" name="force">
             <Variable name="p_Crane.e[1]" unit="force~N"/>
             <Variable name="p_Crane.e[2]" unit="force~N"/>
             <Variable name="p_Crane.e[3]" unit="force~N"/>
diff --git a/test/data/msmi/KnuckleBoomCrane_OspModelDescription.xml b/test/data/msmi/KnuckleBoomCrane_OspModelDescription.xml
index cd654c48d..4985095c1 100644
--- a/test/data/msmi/KnuckleBoomCrane_OspModelDescription.xml
+++ b/test/data/msmi/KnuckleBoomCrane_OspModelDescription.xml
@@ -1,12 +1,13 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<OspModelDescription xmlns="http://opensimulationplatform.com/MSMI/OSPModelDescription">
+<OspModelDescription xmlns="http://opensimulationplatform.com/MSMI/OSPModelDescription"
+                     version="0.1">
     <VariableGroups>
-        <VariableGroup type="effort" name="force">
+        <VariableGroup type="force" name="force">
             <Variable name="p_Crane.e[1]"/>
             <Variable name="p_Crane.e[2]"/>
             <Variable name="p_Crane.e[3]"/>
         </VariableGroup>
-        <VariableGroup type="flow" name="velocity">
+        <VariableGroup type="linear_velocity" name="velocity">
             <Variable name="p_Crane.f[1]"/>
             <Variable name="p_Crane.f[2]"/>
             <Variable name="p_Crane.f[3]"/>
diff --git a/test/data/msmi/schema/OspModelDescription.xsd b/test/data/msmi/schema/OspModelDescription.xsd
index 227dae64b..8cd73395a 100644
--- a/test/data/msmi/schema/OspModelDescription.xsd
+++ b/test/data/msmi/schema/OspModelDescription.xsd
@@ -1,43 +1,68 @@
-<?xml version="1.0" encoding="utf-8" ?>
+<?xml version="1.0" encoding="UTF-8"?>
 <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified"
            targetNamespace="http://opensimulationplatform.com/MSMI/OSPModelDescription"
            xmlns:osp="http://opensimulationplatform.com/MSMI/OSPModelDescription"
            version="0.1">
     <xs:include schemaLocation="fmi2Unit.xsd"/>
-    <xs:element name="OspModelDescription">
-        <xs:complexType>
-            <xs:sequence>
-                <xs:element name="UnitDefinitions" minOccurs="0">
-                    <xs:complexType>
-                        <xs:sequence maxOccurs="unbounded">
-                            <xs:element name="Unit" type="osp:fmi2Unit"/>
-                        </xs:sequence>
-                    </xs:complexType>
-                </xs:element>
-                <xs:element name="VariableGroups" type="osp:variablegroups"/>
-            </xs:sequence>
-            <xs:attribute name="msmiVersion" type="xs:normalizedString" use="required" fixed="0.1">
-                <xs:annotation>
-                    <xs:documentation>MSMI version</xs:documentation>
-                </xs:annotation>
-            </xs:attribute>
-        </xs:complexType>
-    </xs:element>
-    <xs:complexType name="variablegroups">
-        <xs:sequence>
-            <xs:element name="VariableGroup" minOccurs="0" maxOccurs="unbounded">
-                <xs:complexType>
-                    <xs:sequence>
-                        <xs:element name="Variable" maxOccurs="unbounded" type="osp:variable"/>
-                    </xs:sequence>
-                    <xs:attribute name="name" use="required"/>
-                    <xs:attribute name="type" use="required"/>
-                </xs:complexType>
-            </xs:element>
+    <xs:element name="OspModelDescription" type="osp:OspModelDescriptionType"/>
+    <xs:complexType name="UnitDefinitionsType">
+        <xs:sequence minOccurs="0" maxOccurs="unbounded">
+            <xs:element type="osp:fmi2Unit" name="Unit"/>
         </xs:sequence>
     </xs:complexType>
-    <xs:complexType name="variable">
-        <xs:attribute name="name" use="required"/>
-        <xs:attribute name="unit"/>
+    <xs:complexType name="VariableType">
+        <xs:attribute type="xs:string" name="name" use="required"/>
+        <xs:attribute type="xs:string" name="unit" use="optional"/>
+    </xs:complexType>
+    <xs:complexType name="VariableGroupType">
+        <xs:choice maxOccurs="unbounded" minOccurs="0">
+            <xs:element type="osp:VariableType" name="Variable"/>
+            <xs:element type="osp:VariableGroupType" name="VariableGroup"/>
+        </xs:choice>
+        <xs:attribute type="xs:string" name="name" use="required"/>
+        <xs:attribute name="type" use="required">
+            <xs:simpleType>
+                <xs:restriction base="xs:string">
+                    <xs:enumeration value="generic"/>
+
+                    <xs:enumeration value="force"/>
+                    <xs:enumeration value="linear_velocity"/>
+                    <xs:enumeration value="linear_displacement"/>
+
+                    <xs:enumeration value="torque"/>
+                    <xs:enumeration value="angular_velocity"/>
+                    <xs:enumeration value="angular_displacement"/>
+
+                    <xs:enumeration value="voltage"/>
+                    <xs:enumeration value="current"/>
+                    <xs:enumeration value="charge"/>
+
+                    <xs:enumeration value="pressure"/>
+                    <xs:enumeration value="volume_rate_flow"/>
+                    <xs:enumeration value="volume"/>
+
+                    <xs:enumeration value="linear_mechanical_port"/>
+                    <xs:enumeration value="angular_mechanical_port"/>
+                    <xs:enumeration value="electromagnetic_port"/>
+                    <xs:enumeration value="hydraulic_port"/>
+                </xs:restriction>
+            </xs:simpleType>
+        </xs:attribute>
+    </xs:complexType>
+    <xs:complexType name="VariableGroupsType">
+        <xs:sequence minOccurs="0" maxOccurs="unbounded">
+            <xs:element type="osp:VariableGroupType" name="VariableGroup"/>
+        </xs:sequence>
+    </xs:complexType>
+    <xs:complexType name="OspModelDescriptionType">
+        <xs:sequence>
+            <xs:element type="osp:UnitDefinitionsType" name="UnitDefinitions" minOccurs="0"/>
+            <xs:element type="osp:VariableGroupsType" name="VariableGroups"/>
+        </xs:sequence>
+        <xs:attribute name="version" type="xs:string" use="required" fixed="0.1">
+            <xs:annotation>
+                <xs:documentation>OspModelDescription version</xs:documentation>
+            </xs:annotation>
+        </xs:attribute>
     </xs:complexType>
 </xs:schema>