diff --git a/ejb-core/formtemplate/src/main/java/com/silverpeas/workflow/engine/instance/ProcessInstanceImpl.java b/ejb-core/formtemplate/src/main/java/com/silverpeas/workflow/engine/instance/ProcessInstanceImpl.java
index 2d6c5c7f420..763bef05dd6 100644
--- a/ejb-core/formtemplate/src/main/java/com/silverpeas/workflow/engine/instance/ProcessInstanceImpl.java
+++ b/ejb-core/formtemplate/src/main/java/com/silverpeas/workflow/engine/instance/ProcessInstanceImpl.java
@@ -1461,11 +1461,7 @@ public String[] getAssignedStates(User user, String roleName) throws WorkflowExc
       boolean userGroupsMatch = false;
       if (StringUtil.isDefined(wkUser.getGroupId())) {
         // check if one of userGroups matches with working group
-        List<String> groupIds =  Arrays.asList(OrganisationControllerFactory.getOrganisationController()
-            .getAllGroupIdsOfUser(wkUser.getId()));
-        if (groupIds != null) {
-          userGroupsMatch = groupIds.contains(wkUser.getGroupId());
-        }
+        userGroupsMatch = user.getGroupIds().contains(wkUser.getGroupId());
       }
 
       SilverTrace.debug("workflowEngine", "ProcessInstanceImpl.getAssignedStates",
diff --git a/ejb-core/formtemplate/src/main/java/com/silverpeas/workflow/engine/user/UserImpl.java b/ejb-core/formtemplate/src/main/java/com/silverpeas/workflow/engine/user/UserImpl.java
index d09b37f74cc..7ca049945aa 100644
--- a/ejb-core/formtemplate/src/main/java/com/silverpeas/workflow/engine/user/UserImpl.java
+++ b/ejb-core/formtemplate/src/main/java/com/silverpeas/workflow/engine/user/UserImpl.java
@@ -29,7 +29,10 @@
 import com.stratelia.webactiv.beans.admin.AdminReference;
 import com.stratelia.webactiv.beans.admin.UserDetail;
 import com.stratelia.webactiv.beans.admin.UserFull;
+import org.silverpeas.core.admin.OrganisationControllerFactory;
 
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 /**
@@ -120,10 +123,14 @@ public boolean equals(Object user) {
 
   @Override
   public List<String> getGroupIds() {
+    if (groupIds == null) {
+      String[] ids = OrganisationControllerFactory.getOrganisationController().getAllGroupIdsOfUser(getUserId());
+      if (ids != null) {
+        groupIds = Arrays.asList(ids);
+      } else {
+        groupIds = new ArrayList<String>();
+      }
+    }
     return groupIds;
   }
-
-  public void setGroupIds(List<String> groupIds) {
-    this.groupIds = groupIds;
-  }
 }
diff --git a/ejb-core/formtemplate/src/main/java/com/silverpeas/workflow/engine/user/UserManagerImpl.java b/ejb-core/formtemplate/src/main/java/com/silverpeas/workflow/engine/user/UserManagerImpl.java
index 3fa05b8a162..40002bd5e39 100644
--- a/ejb-core/formtemplate/src/main/java/com/silverpeas/workflow/engine/user/UserManagerImpl.java
+++ b/ejb-core/formtemplate/src/main/java/com/silverpeas/workflow/engine/user/UserManagerImpl.java
@@ -69,11 +69,6 @@ public UserManagerImpl() {
   @Override
   public User getUser(String userId) throws WorkflowException {
     UserImpl user = new UserImpl(getUserDetail(userId));
-    String[] groupIds =  OrganisationControllerFactory.getOrganisationController()
-        .getAllGroupIdsOfUser(userId);
-    if (groupIds != null) {
-      user.setGroupIds(Arrays.asList(groupIds));
-    }
     return user;
   }