diff --git a/app/models/dmsf_workflow.rb b/app/models/dmsf_workflow.rb
index 0e7f773b..426390be 100644
--- a/app/models/dmsf_workflow.rb
+++ b/app/models/dmsf_workflow.rb
@@ -57,15 +57,14 @@ class DmsfWorkflow < ActiveRecord::Base
     end
   end
 
-  STATE_NONE = nil
-  STATE_ASSIGNED = 3
-  STATE_WAITING_FOR_APPROVAL = 1
-  STATE_APPROVED = 2
-  STATE_REJECTED = 4
-  STATE_OBSOLETE = 5
+  STATE_ASSIGNED = 3.freeze
+  STATE_WAITING_FOR_APPROVAL = 1.freeze
+  STATE_APPROVED = 2.freeze
+  STATE_REJECTED = 4.freeze
+  STATE_OBSOLETE = 5.freeze
 
-  STATUS_LOCKED = 0
-  STATUS_ACTIVE = 1
+  STATUS_LOCKED = 0.freeze
+  STATUS_ACTIVE = 1.freeze
 
   def participiants
     users = Array.new
diff --git a/app/views/dmsf_files/show.html.erb b/app/views/dmsf_files/show.html.erb
index d95f453e..a65cae75 100644
--- a/app/views/dmsf_files/show.html.erb
+++ b/app/views/dmsf_files/show.html.erb
@@ -87,14 +87,14 @@
           <%= link_to image_tag('download.png'),
             view_dmsf_file_path(@file, :download => revision),
             :title => l(:title_title_version_version_download, :title => h(revision.title), :version => revision.version) %>
+          <%= link_to image_tag('close_hl.png'),
+            obsolete_revision_path(revision),
+            :data => {:confirm => l(:text_are_you_sure)},
+            :title => l(:title_obsolete_revision) if @file_manipulation_allowed && (revision.workflow == DmsfWorkflow::STATE_APPROVED) %>
           <%= link_to image_tag('delete.png'),
             delete_revision_path(revision),
             :data => {:confirm => l(:text_are_you_sure)},
             :title => l(:title_delete_revision) if @file_delete_allowed && (@file.dmsf_file_revisions.visible.count > 1) %>
-          <%= link_to image_tag('/../../plugin_assets/redmine_dmsf/images/obsolete.png'),
-            obsolete_revision_path(revision),
-            :data => {:confirm => l(:text_are_you_sure)},
-            :title => l(:title_obsolete_revision) if @file_manipulation_allowed && (revision.workflow == DmsfWorkflow::STATE_APPROVED) %>
         </div>
         <i><%= l(:info_revision, :rev => revision.id) %></i>
         <%= (revision.source_revision.nil? ? l(:label_created) : l(:label_changed)).downcase %>
diff --git a/app/views/dmsf_links/create.js.erb b/app/views/dmsf_links/create.js.erb
index 7b7c55af..dc87fb4f 100644
--- a/app/views/dmsf_links/create.js.erb
+++ b/app/views/dmsf_links/create.js.erb
@@ -30,7 +30,7 @@ var awf = false;
 <% file = @dmsf_link.target_file %>
 <% if file && !file.locked? && User.current.allowed_to?(:file_approval, file.project) %>
   <% revision = file.last_revision %>
-  <% if revision && (revision.workflow == DmsfWorkflow::STATE_NONE) %>
+  <% if revision && revision.workflow.nil? %>
     awf = true;
   <% end %>
 <% end %>
diff --git a/app/views/dmsf_workflows/_approval_workflow_button.html.erb b/app/views/dmsf_workflows/_approval_workflow_button.html.erb
index d12b44ba..968cbb84 100644
--- a/app/views/dmsf_workflows/_approval_workflow_button.html.erb
+++ b/app/views/dmsf_workflows/_approval_workflow_button.html.erb
@@ -53,7 +53,7 @@
         <% else %>
             <span class="icon"></span>
         <% end %>
-    <% when DmsfWorkflow::STATE_APPROVED, DmsfWorkflow::STATE_REJECTED %>
+    <% when DmsfWorkflow::STATE_APPROVED, DmsfWorkflow::STATE_REJECTED, DmsfWorkflow::STATE_OBSOLETE %>
         <span class="icon-only"></span>
     <% else %>
         <% if workflows_available %>
diff --git a/assets/images/obsolete.png b/assets/images/obsolete.png
deleted file mode 100644
index e69de29b..00000000