diff --git a/src/SMESH/SMESH_subMesh.cxx b/src/SMESH/SMESH_subMesh.cxx
index 5ced47044..a78efcdfc 100644
--- a/src/SMESH/SMESH_subMesh.cxx
+++ b/src/SMESH/SMESH_subMesh.cxx
@@ -104,6 +104,7 @@ SMESH_subMesh::SMESH_subMesh(int                  Id,
     _algoState = NO_ALGO;
     _computeState = NOT_READY;
   }
+  _computeCost = 0; // how costly is to compute this sub-mesh
 }
 
 //=============================================================================
@@ -355,6 +356,35 @@ bool SMESH_subMesh::SubMeshesComputed(bool * isFailedToCompute/*=0*/) const
   return subMeshesComputed;
 }
 
+//================================================================================
+/*!
+ * \brief Return cost of computing this sub-mesh. The cost depends on the shape type
+ * and number of sub-meshes this one DependsOn().
+ *  \return int - the computation cost in abstract units.
+ */
+//================================================================================
+
+int SMESH_subMesh::GetComputeCost() const
+{
+  if ( !_computeCost )
+  {
+    int computeCost;
+    switch ( _subShape.ShapeType() ) {
+    case TopAbs_SOLID:
+    case TopAbs_SHELL: computeCost = 1000; break;
+    case TopAbs_FACE:  computeCost = 100; break;
+    case TopAbs_EDGE:  computeCost = 10; break;
+    default:           computeCost = 1;
+    }
+    SMESH_subMeshIteratorPtr childIt = getDependsOnIterator(/*includeSelf=*/false);
+    while ( childIt->more() )
+      computeCost += childIt->next()->GetComputeCost();
+
+    ((SMESH_subMesh*)this)->_computeCost = computeCost;
+  }
+  return _computeCost;
+}
+
 //=============================================================================
 /*!
  *
@@ -1462,13 +1492,14 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
           break;
         }
         TopoDS_Shape shape = _subShape;
+        int computeCost = GetComputeCost();
         // check submeshes needed
         if (_father->HasShapeToMesh() ) {
           bool subComputed = false, subFailed = false;
           if (!algo->OnlyUnaryInput()) {
             if ( event == COMPUTE /*&&
                  ( algo->NeedDiscreteBoundary() || algo->SupportSubmeshes() )*/)
-              shape = getCollection( gen, algo, subComputed, subFailed );
+              shape = getCollection( gen, algo, subComputed, subFailed, computeCost);
             else
               subComputed = SubMeshesComputed( & subFailed );
           }
@@ -1501,6 +1532,8 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
           OCC_CATCH_SIGNALS;
 #endif
           algo->InitComputeError();
+          algo->GetComputeCost() = computeCost;
+
           MemoryReserve aMemoryReserve;
           SMDS_Mesh::CheckMemory();
           Kernel_Utils::Localizer loc;
@@ -2028,7 +2061,8 @@ void SMESH_subMesh::removeSubMeshElementsAndNodes()
 TopoDS_Shape SMESH_subMesh::getCollection(SMESH_Gen * theGen,
                                           SMESH_Algo* theAlgo,
                                           bool &      theSubComputed,
-                                          bool &      theSubFailed)
+                                          bool &      theSubFailed,
+                                          int  &      theComputeCost)
 {
   theSubComputed = SubMeshesComputed( & theSubFailed );
 
@@ -2048,11 +2082,14 @@ TopoDS_Shape SMESH_subMesh::getCollection(SMESH_Gen * theGen,
   BRep_Builder aBuilder;
   aBuilder.MakeCompound( aCompound );
 
+  theComputeCost = 0;
+
   TopExp_Explorer anExplorer( mainShape, _subShape.ShapeType() );
   for ( ; anExplorer.More(); anExplorer.Next() )
   {
     const TopoDS_Shape& S = anExplorer.Current();
     SMESH_subMesh* subMesh = _father->GetSubMesh( S );
+    theComputeCost += subMesh->GetComputeCost();
     if ( subMesh == this )
     {
       aBuilder.Add( aCompound, S );
@@ -2066,6 +2103,16 @@ TopoDS_Shape SMESH_subMesh::getCollection(SMESH_Gen * theGen,
       if ( !subMesh->SubMeshesComputed() )
         theSubComputed = false;
     }
+    if ( !theAlgo->NeedDiscreteBoundary() )
+    {
+      SMESH_subMeshIteratorPtr smIt = subMesh->getDependsOnIterator(/*includeSelf=*/false);
+      while ( smIt->more() )
+      {
+        SMESH_subMesh* sm = smIt->next();
+        if ( sm->IsEmpty() )
+          theComputeCost += sm->GetComputeCost();
+      }
+    }
   }
 
   return aCompound;
diff --git a/src/SMESH/SMESH_subMesh.hxx b/src/SMESH/SMESH_subMesh.hxx
index 48ed2be01..effe55098 100644
--- a/src/SMESH/SMESH_subMesh.hxx
+++ b/src/SMESH/SMESH_subMesh.hxx
@@ -81,10 +81,11 @@ class SMESH_EXPORT SMESH_subMesh
 
   const std::map < int, SMESH_subMesh * >& DependsOn();
   /*!
-   * \brief Return iterator on the submeshes this one depends on
+   * \brief Return iterator on the sub-meshes this one depends on. By default
+   *        most simple sub-meshes go first.
    */
   SMESH_subMeshIteratorPtr getDependsOnIterator(const bool includeSelf,
-                                                const bool complexShapeFirst) const;
+                                                const bool complexShapeFirst=false) const;
 
   const TopoDS_Shape & GetSubShape() const;
 
@@ -244,7 +245,7 @@ public:
   bool IsEmpty() const;
 
   bool IsMeshComputed() const;
-  // check if _subMeshDS contains mesh elements
+  // check if _subMeshDS contains mesh elements unless _alwaysComputed==true
 
   /*!
    * \brief Allow algo->Compute() if a subshape of lower dim is meshed but
@@ -255,6 +256,8 @@ public:
 
   bool SubMeshesComputed(bool * isFailedToCompute=0) const;
 
+  int GetComputeCost() const;
+  // how costly is to compute this sub-mesh
   
   /*!
    * \brief  Find common submeshes (based on shared subshapes with other
@@ -283,7 +286,8 @@ protected:
   TopoDS_Shape getCollection(SMESH_Gen * theGen,
                              SMESH_Algo* theAlgo,
                              bool &      theSubComputed,
-                             bool &      theSubFailed);
+                             bool &      theSubFailed,
+                             int  &      theComputeCost);
   /*!
    * \brief Update compute_state by _computeError
     * \retval bool - false if there are errors
@@ -318,6 +322,7 @@ protected:
   algo_state            _algoState;
   compute_state         _computeState;
   SMESH_ComputeErrorPtr _computeError;
+  int                   _computeCost; // how costly is to compute this sub-mesh
 
   // allow algo->Compute() if a sub-shape of lower dim is meshed but
   // none mesh entity is bound to it. Eg StdMeshers_CompositeSegment_1D can