diff --git a/src/include/ranges/multi_range.h b/src/include/ranges/multi_range.h
index 8f0b964..a86e99f 100644
--- a/src/include/ranges/multi_range.h
+++ b/src/include/ranges/multi_range.h
@@ -6,12 +6,14 @@
 #include <cstdlib>
 #include <tuple>
 #include <memory>
+#include <map>
 
 //#include "base_def.h"
 #include "ranges/range_base.h"
 #include "ranges/index_base.h"
 
-#include "rpack_num.h"
+#include "ranges/rpack_num.h"
+#include "ranges/multi_range_factory_product_map.h"
 
 namespace MultiArrayTools
 {
@@ -118,6 +120,7 @@ namespace MultiArrayTools
      *   MultiRangeFactory   *
      *************************/
 
+    // NOT THREAD SAVE
     template <class... Ranges>
     class MultiRangeFactory : public RangeFactoryBase
     {
@@ -132,6 +135,11 @@ namespace MultiArrayTools
 	MultiRangeFactory(const std::shared_ptr<ContainerRange<T,Ranges...> >& cr);
 	
 	virtual std::shared_ptr<RangeBase> create() override;
+
+    private:
+	
+	std::shared_ptr<RangeBase> checkIfCreated(const std::tuple<std::shared_ptr<Ranges>...>& ptp);
+	
     };
     
     /******************
@@ -449,9 +457,33 @@ namespace MultiArrayTools
     template <class... Ranges>
     std::shared_ptr<RangeBase> MultiRangeFactory<Ranges...>::create()
     {
+	mProd = checkIfCreated( std::dynamic_pointer_cast<oType>( mProd )->mSpace );
 	setSelf();
 	return mProd;
     }
+
+    template <class... Ranges>
+    std::shared_ptr<RangeBase> MultiRangeFactory<Ranges...>::checkIfCreated(const std::tuple<std::shared_ptr<Ranges>...>& ptp)
+    {
+	std::shared_ptr<RangeBase> out;
+	bool check = false;
+	for(auto& x: MultiRangeFactoryProductMap::mAleadyCreated){
+	    if(x.second.size() == sizeof...(Ranges)){
+		check = RPackNum<sizeof...(Ranges)-1>::checkIfCreated(ptp, x.second);
+		if(check){
+		    out = x.first;
+		    break;
+		}
+	    }
+	}
+	if(not check){
+	    std::vector<std::intptr_t> pv(sizeof...(Ranges));
+	    RPackNum<sizeof...(Ranges)-1>::RangesToVec(ptp, pv);
+	    MultiRangeFactoryProductMap::mAleadyCreated[mProd] = pv;
+	    out = mProd;
+	}
+	return out;
+    }
     
     /******************
      *   MultiRange   *
diff --git a/src/include/ranges/multi_range_factory_product_map.h b/src/include/ranges/multi_range_factory_product_map.h
new file mode 100644
index 0000000..c6b10df
--- /dev/null
+++ b/src/include/ranges/multi_range_factory_product_map.h
@@ -0,0 +1,25 @@
+
+#ifndef __multi_range_factory_product_map_h__
+#define __multi_range_factory_product_map_h__
+
+#include <memory>
+#include <vector>
+#include <map>
+#include "ranges/rbase_def.h"
+
+namespace MultiArrayTools
+{
+    class MultiRangeFactoryProductMap
+    {
+    public:
+
+	template <class... Ranges>
+	friend class MultiRangeFactory;
+	
+    private:
+	static std::map<std::shared_ptr<RangeBase>,std::vector<std::intptr_t> > mAleadyCreated;
+    };
+    
+}
+
+#endif
diff --git a/src/include/ranges/rpack_num.h b/src/include/ranges/rpack_num.h
index bfbc05d..c348e41 100644
--- a/src/include/ranges/rpack_num.h
+++ b/src/include/ranges/rpack_num.h
@@ -227,7 +227,14 @@ namespace MultiArrayHelper
 				       std::vector<std::shared_ptr<RangeBase> >& v)
 	{
 	    setRangeToVec(v, std::get<N>(rst));
-	    //v[N] = std::get<N>(rst);
+	    RPackNum<N-1>::RangesToVec(rst, v);
+	}
+
+	template <class... Ranges>
+	static inline void RangesToVec(const std::tuple<std::shared_ptr<Ranges>...>& rst,
+				       std::vector<std::intptr_t>& v)
+	{
+	    v[N] = reinterpret_cast<std::intptr_t>( std::get<N>(rst).get() );
 	    RPackNum<N-1>::RangesToVec(rst, v);
 	}
 
@@ -285,6 +292,14 @@ namespace MultiArrayHelper
 	    resolveSetRange(std::get<tps-N-1>(rtp), orig, off, size);
 	    RPackNum<N-1>::resolveRangeType(orig, rtp, off+size, sizes...);
 	}
+
+	template <class... Ranges>
+	static inline bool checkIfCreated(const std::tuple<std::shared_ptr<Ranges>...>& p,
+					  const std::vector<std::intptr_t>& a)
+	{
+	    return reinterpret_cast<std::intptr_t>( std::get<N>(p).get() ) == a[N] and
+		RPackNum<N-1>::checkIfCreated(p,a);
+	}
     };
 
     
@@ -416,6 +431,13 @@ namespace MultiArrayHelper
 	    return 1;
 	}
 
+	template <class... Ranges>
+	static inline void RangesToVec(const std::tuple<std::shared_ptr<Ranges>...>& rst,
+				       std::vector<std::intptr_t>& v)
+	{
+	    v[0] = reinterpret_cast<std::intptr_t>( std::get<0>(rst).get() );;
+	}
+	
 	template <class... Ranges>
 	static inline void RangesToVec(const std::tuple<std::shared_ptr<Ranges>...>& rst,
 				       std::vector<std::shared_ptr<RangeBase> >& v)
@@ -472,6 +494,13 @@ namespace MultiArrayHelper
 	    resolveSetRange(std::get<tps-1>(rtp), orig, off, size);
 	}
 
+	template <class... Ranges>
+	static inline bool checkIfCreated(const std::tuple<std::shared_ptr<Ranges>...>& p,
+					  const std::vector<std::intptr_t>& a)
+	{
+	    return reinterpret_cast<std::intptr_t>( std::get<0>(p).get() ) == a[0];
+	}
+
     };
     
     template <IndexType IT>
diff --git a/src/lib/CMakeLists.txt b/src/lib/CMakeLists.txt
index bffe052..c2c6a05 100644
--- a/src/lib/CMakeLists.txt
+++ b/src/lib/CMakeLists.txt
@@ -2,6 +2,7 @@
 set(libmultiarray_a_SOURCES
   ${CMAKE_SOURCE_DIR}/src/lib/ranges/range_base.cc
   ${CMAKE_SOURCE_DIR}/src/lib/ranges/anonymous_range.cc
+  ${CMAKE_SOURCE_DIR}/src/lib/ranges/multi_range_factory_product_map.cc
   )
 
 file(GLOB cc_files "${CMAKE_SOURCE_DIR}/src/lib/ranges/range_types/*.cc")
diff --git a/src/lib/ranges/multi_range_factory_product_map.cc b/src/lib/ranges/multi_range_factory_product_map.cc
new file mode 100644
index 0000000..30da2dc
--- /dev/null
+++ b/src/lib/ranges/multi_range_factory_product_map.cc
@@ -0,0 +1,7 @@
+
+#include "ranges/multi_range_factory_product_map.h"
+
+namespace MultiArrayTools
+{
+    std::map<std::shared_ptr<RangeBase>,std::vector<std::intptr_t> > MultiRangeFactoryProductMap::mAleadyCreated;
+}