diff --git a/mo/src/perturb/moMonOpPerturb.h b/mo/src/perturb/moMonOpPerturb.h
index c056bbf6a..a4bcea574 100644
--- a/mo/src/perturb/moMonOpPerturb.h
+++ b/mo/src/perturb/moMonOpPerturb.h
@@ -48,8 +48,9 @@ public:
      * Constructor
      * @param _monOp an eoMonOp (pertubation operator)
      * @param _fullEval a full evaluation function
+     * @param _nbPerturbation number of operator executions for perturbation
      */
-    moMonOpPerturb(eoMonOp<EOT>& _monOp, eoEvalFunc<EOT>& _fullEval):monOp(_monOp), fullEval(_fullEval) {}
+  moMonOpPerturb(eoMonOp<EOT>& _monOp, eoEvalFunc<EOT>& _fullEval, unsigned int _nbPerturbation = 1):monOp(_monOp), fullEval(_fullEval), nbPerturbation(_nbPerturbation) {}
 
     /**
      * Apply monOp on the solution
@@ -57,16 +58,22 @@ public:
      * @return value of monOp
      */
     bool operator()(EOT& _solution) {
-        bool res = monOp(_solution);
-	_solution.invalidate();
-        fullEval(_solution);
-        return res;
+      bool res = false;
+
+      for(unsigned int i = 0; i < nbPerturbation; i++)
+	res = res || monOp(_solution);
+      
+      _solution.invalidate();
+      fullEval(_solution);
+
+      return res;
     }
 
 private:
-    /** monOp */
-    eoMonOp<EOT>& monOp;
-    eoEvalFunc<EOT>& fullEval;
+  /** monOp */
+  eoMonOp<EOT>& monOp;
+  eoEvalFunc<EOT>& fullEval;
+  unsigned int nbPerturbation;
 };
 
 #endif
diff --git a/mo/src/problems/eval/moQAPIncrEval.h b/mo/src/problems/eval/moQAPIncrEval.h
index 3fd529a7f..5c47623d9 100644
--- a/mo/src/problems/eval/moQAPIncrEval.h
+++ b/mo/src/problems/eval/moQAPIncrEval.h
@@ -61,10 +61,10 @@ public:
     int d; 
     int k;
     
-    unsigned i, j;
-
-    _neighbor.getIndices(n, i, j);
+    unsigned i = _neighbor.first();
+    unsigned j = _neighbor.second();
 
+    //    _neighbor.getIndices(n, i, j);
     d = (A[i][i]-A[j][j])*(B[_solution[j]][_solution[j]]-B[_solution[i]][_solution[i]]) +
       (A[i][j]-A[j][i])*(B[_solution[j]][_solution[i]]-B[_solution[i]][_solution[j]]);
     
diff --git a/mo/src/problems/permutation/moIndexedSwapNeighbor.h b/mo/src/problems/permutation/moIndexedSwapNeighbor.h
index 06491f134..d30305100 100644
--- a/mo/src/problems/permutation/moIndexedSwapNeighbor.h
+++ b/mo/src/problems/permutation/moIndexedSwapNeighbor.h
@@ -107,6 +107,22 @@ public:
     index( _first + n * (n - 1) / 2 );
   }
 
+  /**
+   * Getter of the firt location
+   * @return first indice
+   */
+  unsigned int first() {
+    return indices.first;
+  }
+
+  /**
+   * Getter of the second location
+   * @return second indice
+   */
+  unsigned int second() {
+    return indices.second;
+  }
+
 private:
   std::pair<unsigned int, unsigned int> indices;