diff --git a/product/ERP5/Tool/TemplateTool.py b/product/ERP5/Tool/TemplateTool.py
index b5798b59079a468811df0f56de5f91dd52bebb13..9e5f619c6677c49874e6e3afe84929daadc5750c 100644
--- a/product/ERP5/Tool/TemplateTool.py
+++ b/product/ERP5/Tool/TemplateTool.py
@@ -1648,11 +1648,11 @@ class TemplateTool (BaseTool):
       else:
         # Summation should also consider arithmetic on the Business Item(s)
         # having same path and layer and combine them.
-        combinedBM = sum(bm_list)
+        combinedBM = reduce(lambda x, y: x+y, bm_list)
 
       # XXX: We are missing the part of creating installed_BM for all the BM
       # we have in bm_list, because this would be needed in case we build
-      # Business Manager again
+      # Business Manager again.
 
       # Reduce the final Business Manager
       combinedBM.reduceBusinessManager()
@@ -1661,8 +1661,8 @@ class TemplateTool (BaseTool):
       return combinedBM
 
     security.declareProtected(Permissions.ManagePortal,
-            'installMultipleBusinessManager')
-    def installMultipleBusinessManager(self, bm):
+            'installBusinessManager')
+    def installBusinessManager(self, bm):
       """
       Run installation on flattened Business Manager
       """
@@ -1673,6 +1673,16 @@ class TemplateTool (BaseTool):
       else:
         raise ValueError, 'Business Manager not flattened, cannot install'
 
+    security.declareProtected(Permissions.ManagePortal,
+            'installMultipleBusinessManager')
+    def installMultipleBusinessManager(self, bm_list):
+      """
+      Run installation on flattened Business Manager
+      """
+      combinedBM = self.combineMultipleBusinessManager(bm_list)
+      self.installBusinessManager(combinedBM)
+
+
     security.declareProtected(Permissions.ManagePortal,
             'getBusinessTemplateUrl')
     def getBusinessTemplateUrl(self, base_url_list, bt5_title):