diff --git a/plugins/xmlsave/src/testsuite/test-xml_visitor.cc b/plugins/xmlsave/src/testsuite/test-xml_visitor.cc
index 4a6cc9a..2b72c5e 100644
--- a/plugins/xmlsave/src/testsuite/test-xml_visitor.cc
+++ b/plugins/xmlsave/src/testsuite/test-xml_visitor.cc
@@ -47,7 +47,7 @@ void fillHistory(History &hist)
   cout << "resource name: " << respair.second->get_name() << " key: " << respair.first << " places: " << respair.second->get_places() << endl;
 
   // add a process - name, arrival time, priority
-  Process&   p1 =  hist.add_process(Glib::ustring("Process 1"), 5, 2); // name, arrival time, priority
+  Process&   p1 =  hist.add_process(Glib::ustring("Process 1"), 0, 2); // name, arrival time, priority
   // and print his values
   cout << "process name: " << p1.get_name() << " arrival_time: " << p1.get_arrival_time() << " base_priority: " << p1.get_base_priority() << endl;
 
@@ -62,12 +62,17 @@ void fillHistory(History &hist)
   cout << "process name: " << p3.get_name() << " arrival_time: " << p3.get_arrival_time() << " base_priority: " << p3.get_base_priority() << endl;
 
   // add a thread - name, parent, cpu time, arrival time, priority
-  Thread&   p1_t1 =  hist.add_thread(Glib::ustring("Process 1 - Thread 1"), p1, 3, 2, 6);
+  Thread&   p1_t1 =  hist.add_thread(Glib::ustring("Process 1 - Thread 1"), p1, 8, 2, 6);
   // and print his values
   cout << "thread name: " << p1_t1.get_name() << " total_cpu_time: " << p1_t1.get_total_cpu_time() << " arrival_time: " << p1_t1.get_arrival_time() << " base_priority: " << p1_t1.get_base_priority() << endl;
 
+  // add a thread - name, parent, cpu time, arrival time, priority
+  Thread&   p1_t2 =  hist.add_thread(Glib::ustring("Process 1 - Thread 2"), p1, 3, 3, 5);
+  // and print his values
+  cout << "thread name: " << p1_t2.get_name() << " total_cpu_time: " << p1_t2.get_total_cpu_time() << " arrival_time: " << p1_t2.get_arrival_time() << " base_priority: " << p1_t2.get_base_priority() << endl;
+
   // add a request - Thread, time
-  Request&   req1 =  hist.add_request(p1_t1, 7);
+  Request&   req1 =  hist.add_request(p1_t1, 3);
   // and print his values
   cout << "request arrival_time: " << req1.get_instant() << endl;
 
@@ -79,8 +84,14 @@ void fillHistory(History &hist)
 }
 
 
+void showHistory(const History &hist)
+{
+  
+}
+
 void dumpEnvironment(const Environment& env)
 {
+  cout << "dump environment start " <<endl;
   const Environment::Processes& pvect = env.get_processes();
   typedef std::vector<Process*>::const_iterator proc_iterator;
 
@@ -89,7 +100,7 @@ void dumpEnvironment(const Environment& env)
   while(iter!=end)
   {
     Process* p = (*iter);
-    cout << "process name: " << p->get_name() << " arrival_time: " << p->get_arrival_time() << " base_priority: " << p->get_base_priority() << endl;
+    cout << "  process name: " << p->get_name() << " arrival_time: " << p->get_arrival_time() << " base_priority: " << p->get_base_priority() << endl;
     iter++;
   
 
@@ -101,13 +112,43 @@ void dumpEnvironment(const Environment& env)
     while(iter1!=end1)
     {
       
-      Thread* p = (*iter1);
-      cout << "Thread name: " << p->get_name() << " arrival_time: " << p->get_arrival_time() << " base_priority: " << p->get_base_priority() << endl;
+      Thread* t = (*iter1);
+      cout << "    thread name: " << t->get_name() << " arrival_time: " << t->get_arrival_time() << " base_priority: " << t->get_base_priority() << endl;
+      
+      typedef std::vector<Request*> Requests;
+      typedef std::vector<Request*>::const_iterator req_iterator;
+      const Requests& rvect = t->get_requests();
+      req_iterator iter2 = rvect.begin();
+      req_iterator end2  = rvect.end();
+      while(iter2!=end2)
+      {
+        
+        Request* r = (*iter2);
+        cout << "      request arrival_time: " << r->get_instant() << endl;
+
+        typedef std::vector<SubRequest*> SubRequests;
+        typedef std::vector<SubRequest*>::const_iterator subreq_iterator;
+        const SubRequests& srvect = r->get_subrequests();
+        subreq_iterator iter3 = srvect.begin();
+        subreq_iterator end3  = srvect.end();
+        while(iter3!=end3)
+        {
+          
+          SubRequest* sr = (*iter3);
+          cout << "        sub request resource_key: " << sr->get_resource_key() << " places: " << sr->get_places() << " length: " << sr->get_length() << endl;
+          iter3++;
+        }
+
+        
+        iter2++;
+      }
+
       iter1++;
     }
 
 
   }
+  cout << "dump environment end " << endl << endl;
 }
 
 
@@ -118,14 +159,21 @@ main(int argc, char** argv)
 
   ConcreteHistory hist;
 
+  cout << "fill history " << endl;
   fillHistory(hist);
 
+  cout << "history " << endl;
   const Environment& env = hist.get_last_environment();
   dumpEnvironment(env);
 
   XMLSerializer xmlser;
   xmlser.save_snapshot(Glib::ustring("xml-visit.xml"), hist);
 
+  ConcreteHistory hist2;
+  xmlser.restore_snapshot(Glib::ustring("xml-visit.xml"), hist2);
+  
+  cout << "history2 - copy of history " << endl;
+  dumpEnvironment(hist2.get_last_environment());
 
   // typedef std::vector<Process*>    Processes;
 	return 0;
diff --git a/plugins/xmlsave/src/xml_serializer.cc b/plugins/xmlsave/src/xml_serializer.cc
index 13869cd..e543d51 100644
--- a/plugins/xmlsave/src/xml_serializer.cc
+++ b/plugins/xmlsave/src/xml_serializer.cc
@@ -198,6 +198,25 @@ void XMLSerializer::fill_schedulables(xmlNodePtr schedulables_node, const Histor
     }
 }
 
+void XMLSerializer::clear_history(History& hist)
+{
+/*
+    const Environment& env = hist.get_last_environment();
+
+    const Environment::Processes& pvect = env.get_processes();
+    typedef std::vector<Process*>::const_iterator proc_iterator;
+  
+    proc_iterator iter = pvect.begin();
+    proc_iterator end = pvect.end();
+    while(iter!=end)
+    {
+      xvisit.from_process(*(*iter));
+      pvect.
+      iter = pvect.begin();
+    }
+*/
+}
+
 void XMLSerializer::read_doc(xmlDocPtr doc, XMLSerializerFactory& fact)
 {
     /*
@@ -211,13 +230,13 @@ void XMLSerializer::read_doc(xmlDocPtr doc, XMLSerializerFactory& fact)
       throw SerializerError("Reading Error: xml doc is empty.");
     }
 
-    cout << "ROOT: " << root->name << endl;
+    // cout << "ROOT: " << root->name << endl;
 
     xmlNodePtr cur;
     cur = root->children;
     while(cur!=NULL)
     {
-      cout << "NODE: " << cur->name << endl;
+      // cout << "NODE: " << cur->name << endl;
       
       Glib::ustring name((const char *)cur->name);
       if(name=="resources")
@@ -239,25 +258,25 @@ XMLSerializerFactory::Parameters* read_properties(xmlAttrPtr prop)
     
   XMLSerializerFactory::Parameters* par=new XMLSerializerFactory::Parameters();
   while (prop != NULL) {
-    // cout << "PROP: " << prop->name;
+    // // cout << "PROP: " << prop->name;
 
     if(prop->children && xmlNodeIsText(prop->children)){
       xmlChar *key = xmlNodeGetContent (prop->children);
       // xmlChar *key = xmlNodeListGetString(doc, prop->children, 1);
       if(key!=NULL)
       {
-        // cout << " VALUE: " <<  key;
+        // // cout << " VALUE: " <<  key;
         std::pair<Glib::ustring, Glib::ustring> key_value(Glib::ustring((const char *)prop->name), Glib::ustring((const char *)key));
         par->insert(key_value);
         // c.insert(typename Cont::value_type(new_key, pos->second));
-        cout << " pair PROP: " <<  key_value.first << " VALUE: " <<  key_value.second << endl;
+        // cout << " pair PROP: " <<  key_value.first << " VALUE: " <<  key_value.second << endl;
         
         xmlFree(key);
       }
-      else
-        cout << " !VALUE IS NULL! ";
+      // else
+        // cout << " !VALUE IS NULL! ";
     }
-    cout << endl;
+    // cout << endl;
     prop = prop->next;
   }
   return par;
@@ -272,7 +291,7 @@ void XMLSerializer::read_resources(xmlNodePtr resources_node, XMLSerializerFacto
       Glib::ustring node_name((const char *)cur->name);
       if(node_name=="resource")
       {
-        cout << "NODE: " << cur->name << endl;
+        // cout << "read_resources NODE: " << cur->name << endl;
   
         xmlAttrPtr prop = cur->properties;
         XMLSerializerFactory::Parameters* par=read_properties(prop);
@@ -288,34 +307,118 @@ void XMLSerializer::read_resources(xmlNodePtr resources_node, XMLSerializerFacto
 }
 void XMLSerializer::read_schedulables(xmlNodePtr schedulables_node, XMLSerializerFactory& fact)
 {
+    if(schedulables_node==NULL)
+      return;
+    
     xmlNodePtr cur;
     cur = schedulables_node->children;
     while(cur!=NULL)
     {
-      cout << "NODE: " << cur->name << endl;
-
-      xmlAttrPtr prop = cur->properties;
-      while (prop != NULL) {
-        cout << "PROP: " << prop->name;
-    
-        if(prop->children && xmlNodeIsText(prop->children)){
-          xmlChar *key = xmlNodeGetContent (prop->children);
-          // xmlChar *key = xmlNodeListGetString(doc, prop->children, 1);
-          if(key!=NULL)
-          {
-            cout << " VALUE: " <<  key;
-            xmlFree(key);
-          }
-          else
-            cout << " !VALUE IS NULL! ";
+      Glib::ustring node_name((const char *)cur->name);
+      if(node_name=="process")
+      {
+        // cout << "read_schedulables NODE: " << cur->name << endl;
+  
+        xmlAttrPtr prop = cur->properties;
+        XMLSerializerFactory::Parameters* par=read_properties(prop);
+        if(par!=NULL)
+        {
+          fact.factory_method(Glib::ustring("Process"), *par);
         }
-        cout << endl;
-        prop = prop->next;
+        // pass the "threads node"
+        read_threads(cur->children, fact);
       }
 
       cur = cur->next;
     }
 }
 
+void XMLSerializer::read_threads(xmlNodePtr threads_node, XMLSerializerFactory& fact)
+{
+    if(threads_node==NULL)
+      return;
+    
+    xmlNodePtr cur;
+    cur = threads_node->children;
+    while(cur!=NULL)
+    {
+      Glib::ustring node_name((const char *)cur->name);
+      if(node_name=="thread")
+      {
+        // cout << "read_threads NODE: " << cur->name << endl;
+  
+        xmlAttrPtr prop = cur->properties;
+        XMLSerializerFactory::Parameters* par=read_properties(prop);
+        if(par!=NULL)
+        {
+          fact.factory_method(Glib::ustring("Thread"), *par);
+        }
+        // pass the "requests node"
+        read_requests(cur->children, fact);
+      }
+
+      cur = cur->next;
+    }
+}
+
+void XMLSerializer::read_requests(xmlNodePtr requests_node, XMLSerializerFactory& fact)
+{
+    if(requests_node==NULL)
+    {
+      // cout << "read_requests NULL" << endl;
+      return;
+    }
+    
+    xmlNodePtr cur;
+    cur = requests_node->children;
+    while(cur!=NULL)
+    {
+      Glib::ustring node_name((const char *)cur->name);
+      if(node_name=="request")
+      {
+        // cout << "read_requests NODE: " << cur->name << endl;
+  
+        xmlAttrPtr prop = cur->properties;
+        XMLSerializerFactory::Parameters* par=read_properties(prop);
+        if(par!=NULL)
+        {
+          fact.factory_method(Glib::ustring("Request"), *par);
+        }
+        // pass the "subrequest nodes"
+        read_subrequests(cur->children, fact);
+      }
+
+      cur = cur->next;
+    }
+}
+
+void XMLSerializer::read_subrequests(xmlNodePtr subrequest_node, XMLSerializerFactory& fact)
+{
+    if(subrequest_node==NULL)
+    {
+      // cout << "read_subrequest NULL" << endl;
+      return;
+    }
+    
+    xmlNodePtr cur;
+    cur = subrequest_node;
+    while(cur!=NULL)
+    {
+      Glib::ustring node_name((const char *)cur->name);
+      if(node_name=="subrequest")
+      {
+        // cout << "read_subrequest NODE: " << cur->name << endl;
+  
+        xmlAttrPtr prop = cur->properties;
+        XMLSerializerFactory::Parameters* par=read_properties(prop);
+        if(par!=NULL)
+        {
+          fact.factory_method(Glib::ustring("SubRequest"), *par);
+        }
+      }
+
+      cur = cur->next;
+    }
+}
 
 /* comment */
diff --git a/plugins/xmlsave/src/xml_serializer.hh b/plugins/xmlsave/src/xml_serializer.hh
index 93bbb3f..79743ac 100644
--- a/plugins/xmlsave/src/xml_serializer.hh
+++ b/plugins/xmlsave/src/xml_serializer.hh
@@ -52,9 +52,13 @@ namespace sgpem
     void fill_resources(xmlNodePtr resources_node, const History& hist);
     void fill_schedulables(xmlNodePtr schedulables_node, const History& hist);
 
+    void clear_history(History& hist);
     void read_doc(xmlDocPtr doc, XMLSerializerFactory& fact);
     void read_resources(xmlNodePtr resources_node, XMLSerializerFactory& fact);
     void read_schedulables(xmlNodePtr schedulables_node, XMLSerializerFactory& fact);
+    void read_threads(xmlNodePtr schedulables_node, XMLSerializerFactory& fact);
+    void read_requests(xmlNodePtr schedulables_node, XMLSerializerFactory& fact);
+    void read_subrequests(xmlNodePtr schedulables_node, XMLSerializerFactory& fact);
   };
 }
 
diff --git a/plugins/xmlsave/src/xml_serializer_factory.cc b/plugins/xmlsave/src/xml_serializer_factory.cc
index 676d047..b076372 100644
--- a/plugins/xmlsave/src/xml_serializer_factory.cc
+++ b/plugins/xmlsave/src/xml_serializer_factory.cc
@@ -58,19 +58,27 @@ XMLSerializerFactory::factory_method(const Glib::ustring& class_name, Parameters
   }
   else if(class_name == "Process")
   {
+    create_process(parameters);
   }
   else if(class_name == "Thread")
   {
+    create_thread(parameters);
   }
   else if(class_name == "Request")
   {
+    create_request(parameters);
   }
   else if(class_name == "SubRequest")
   {
+    create_subrequest(parameters);
+  }
+  else 
+  {
+    throw SerializerError("Factory for Unknown class: " + class_name + " doesn't exists.");
   }
 }
 
-XMLSerializerFactory::ResourcePair
+History::ResourcePair
 XMLSerializerFactory::create_resource(Parameters& parameters)
 {
   // if(_hist!=NULL)
@@ -81,6 +89,7 @@ XMLSerializerFactory::create_resource(Parameters& parameters)
     int arrival_time=0;
     int how_many=1;
     bool preemptable=false;
+    int old_key;
     Parameters::iterator pos;
     
     // read "name" property
@@ -93,6 +102,7 @@ XMLSerializerFactory::create_resource(Parameters& parameters)
     pos = parameters.find(Glib::ustring("key"));
     if (pos != parameters.end()) {
       key = pos->second;
+      string_to_int(key, old_key);
     }
     
     // read "preemptable" property
@@ -115,6 +125,7 @@ XMLSerializerFactory::create_resource(Parameters& parameters)
 
    
     History::ResourcePair respair = _hist->add_resource(name, preemptable, how_many, arrival_time);
+    _temp_map.insert(TempMap::value_type((resource_key_t)old_key, respair.first));
 
     return respair;
   }
@@ -150,24 +161,115 @@ XMLSerializerFactory::create_process(Parameters& parameters)
       string_to_int(pos->second, priority);
     }
 
-
-    return _hist->add_process(Glib::ustring(name, arrival_time, priority);;
+    _last_process = &_hist->add_process(name, arrival_time, priority);
+    return *_last_process;
   }
 }
 
+
+
 Thread&
 XMLSerializerFactory::create_thread(Parameters& parameters)
 {
+  // if(_hist!=NULL)
+  {
+
+    Glib::ustring name;
+    int arrival_time=0;
+    int lasts_for=0;
+    int priority=1;
+    Parameters::iterator pos;
+    
+    // read "name" property
+    pos = parameters.find(Glib::ustring("name"));
+    if (pos != parameters.end()) {
+      name = pos->second;
+    }
+
+    // read "arrival-time" property
+    pos = parameters.find(Glib::ustring("arrival-time"));
+    if (pos != parameters.end()) {
+      string_to_int(pos->second, arrival_time);
+    }
+    
+    // read "priority" property
+    pos = parameters.find(Glib::ustring("priority"));
+    if (pos != parameters.end()) {
+      string_to_int(pos->second, priority);
+    }
+
+    // read "priority" property
+    pos = parameters.find(Glib::ustring("lasts-for"));
+    if (pos != parameters.end()) {
+      string_to_int(pos->second, lasts_for);
+    }
+
+    _last_thread = &_hist->add_thread(name, *_last_process, lasts_for, arrival_time, priority);
+    return *_last_thread;
+  }
 }
 
 Request&
 XMLSerializerFactory::create_request(Parameters& parameters)
 {
+  // if(_hist!=NULL)
+  {
+
+    int arrival_time=0;
+    Parameters::iterator pos;
+
+    // read "arrival-time" property
+    pos = parameters.find(Glib::ustring("arrival-time"));
+    if (pos != parameters.end()) {
+      string_to_int(pos->second, arrival_time);
+    }
+
+    _last_request = &_hist->add_request(*_last_thread, arrival_time);
+    return *_last_request;
+  }
 }
 
-Subrequest&
+SubRequest&
 XMLSerializerFactory::create_subrequest(Parameters& parameters)
 {
+  // if(_hist!=NULL)
+  {
+
+    int old_key=0;
+    int lasts_for=0;
+    int places=1;
+    Parameters::iterator pos;
+    resource_key_t new_key = 0;
+    
+    
+    // read "arrival-time" property
+    pos = parameters.find(Glib::ustring("resource"));
+    if (pos != parameters.end()) {
+      string_to_int(pos->second, old_key);
+      
+      TempMap::iterator temp_pos;
+      temp_pos = _temp_map.find((resource_key_t)old_key);
+      if (temp_pos != _temp_map.end()) {
+        //take key of resource in _hist
+        new_key = temp_pos->second;
+      }
+    }
+    
+    // read "priority" property
+    pos = parameters.find(Glib::ustring("how-many"));
+    if (pos != parameters.end()) {
+      string_to_int(pos->second, places);
+    }
+
+    // read "priority" property
+    pos = parameters.find(Glib::ustring("lasts-for"));
+    if (pos != parameters.end()) {
+      string_to_int(pos->second, lasts_for);
+    }
+
+    return _hist->add_subrequest(*_last_request, new_key, (History::time_t)lasts_for, (History::size_t)places);
+  }
+  // add a sub request - Request, resource_key, duration, places
 }
 
 
diff --git a/plugins/xmlsave/src/xml_serializer_factory.hh b/plugins/xmlsave/src/xml_serializer_factory.hh
index c99f40f..5928b61 100644
--- a/plugins/xmlsave/src/xml_serializer_factory.hh
+++ b/plugins/xmlsave/src/xml_serializer_factory.hh
@@ -22,7 +22,7 @@
 #define XML_SERIALIZER_FACTORY_HH 1
 
 #include "config.h"
-// #include "history.hh"
+#include "history.hh"
 #include "environment.hh"
 
 #include <glibmm/ustring.h>
@@ -35,7 +35,7 @@ namespace sgpem
   class Process;
   class Thread;
   class Request;
-  class Subrequest;
+  class SubRequest;
 }
 
 namespace sgpem
@@ -51,20 +51,35 @@ namespace sgpem
     History* get_history();
 
     typedef Environment::resource_key_t      resource_key_t;
-    typedef const std::pair<resource_key_t, Resource*>  ResourcePair;
-    //typedef const std::map<const Glib::ustring&, const Glib::ustring&> Parameters;
+    // typedef const std::pair<resource_key_t, Resource*>  ResourcePair;
+    //NOUSE typedef const std::map<const Glib::ustring&, const Glib::ustring&> Parameters;
+    // associate old keys with new ones
     typedef std::map<Glib::ustring, Glib::ustring> Parameters;
 
+    // associate old keys with new ones
+    //typedef pair<resource_key_t, resource_key_t> TempPair;
+    typedef std::map<resource_key_t, resource_key_t> TempMap;
+
     void factory_method(const Glib::ustring& class_name, Parameters& parameters);
   protected:
   private:
-    ResourcePair create_resource(Parameters& parameters);
+    History::ResourcePair create_resource(Parameters& parameters);
     Process& create_process(Parameters& parameters);
     Thread& create_thread(Parameters& parameters);
     Request& create_request(Parameters& parameters);
-    Subrequest& create_subrequest(Parameters& parameters);
+    SubRequest& create_subrequest(Parameters& parameters);
 
+    // history object to add to resources processes etc...
     History* _hist;
+
+    // memory of last objects to link to
+    Process* _last_process;
+    Thread*  _last_thread;
+    Request* _last_request;
+
+    // take association with old keys an new keys
+    // to reslove sub requests
+    TempMap _temp_map;
   };
 }
 
diff --git a/plugins/xmlsave/src/xml_visitor.cc b/plugins/xmlsave/src/xml_visitor.cc
index 755c6b2..4883047 100644
--- a/plugins/xmlsave/src/xml_visitor.cc
+++ b/plugins/xmlsave/src/xml_visitor.cc
@@ -220,7 +220,7 @@ void XMLVisitor::from_request(xmlNodePtr parent, const Request& obj)
     while(iter!=end)
     {
       const SubRequest* sr = *iter;
-      cout << "SUB REQUEST: " << sr->get_resource_key() << " places: " << sr->get_places() << " length: " << sr->get_length() << endl;
+      // cout << "SUB REQUEST: " << sr->get_resource_key() << " places: " << sr->get_places() << " length: " << sr->get_length() << endl;
       from_subrequest(request_node, *(*iter));
       iter++;
     }