diff --git a/plugins/pyloader/src/ScriptAdapter.py b/plugins/pyloader/src/ScriptAdapter.py
index 1eb5583..758e910 100644
--- a/plugins/pyloader/src/ScriptAdapter.py
+++ b/plugins/pyloader/src/ScriptAdapter.py
@@ -82,32 +82,6 @@ class ScriptAdapter :
         self._ret_val = self._policy.is_preemptive()
         self._g_mutex.unlock()
     
-    ## @brief Asynchronously call Policy.get_time_slice()
-    #
-    # @param self The caller object
-    def async_get_time_slice(self):
-        self._g_mutex.lock(ScriptAdapter._wrap_get_time_slice, self)
-
-    def _wrap_get_time_slice(self):
-        thread.start_new_thread(ScriptAdapter._wrap_get_time_slice_callback, (self,))
-
-    def _wrap_get_time_slice_callback(self):
-        self._ret_val = self._policy.get_time_slice()
-        self._g_mutex.unlock()
-
-    ## @brief Asynchronously call Policy.wants()
-    #
-    # @param self The caller object
-    def async_wants(self):
-        self._g_mutex.lock(ScriptAdapter._wrap_wants, self)
-
-    def _wrap_wants(self):
-        thread.start_new_thread(ScriptAdapter._wrap_wants_callback, (self,))
-
-    def _wrap_wants_callback(self):
-        self._ret_val = self._policy.wants()
-        self._g_mutex.unlock()
-
     ## @brief Return the global shared variable with the methods' last return value
     def get_return_value(self):
         return self._ret_val
diff --git a/plugins/pyloader/src/builtin-policies/fcfs.py b/plugins/pyloader/src/builtin-policies/fcfs.py
index 805c62b..cbf62c1 100644
--- a/plugins/pyloader/src/builtin-policies/fcfs.py
+++ b/plugins/pyloader/src/builtin-policies/fcfs.py
@@ -36,9 +36,6 @@ class fcfs(Policy) :
     def get_time_slice(self):
         return -2
 
-    def wants(self):
-	return policy_sorts_processes
-
     def sort_queue(self, queue):
         cmpf = lambda a, b: \
             a.get_arrival_time() < \
diff --git a/plugins/pyloader/src/builtin-policies/sjf.py b/plugins/pyloader/src/builtin-policies/sjf.py
index 12707b3..4227d47 100644
--- a/plugins/pyloader/src/builtin-policies/sjf.py
+++ b/plugins/pyloader/src/builtin-policies/sjf.py
@@ -36,9 +36,6 @@ class sjf(Policy) :
     def get_time_slice(self):
         return -1
 
-    def wants(self):
-	return policy_sorts_processes
-
     def sort_queue(self, queue):
         cmpf = lambda a, b: \
             a.get_remaining_time() < \
diff --git a/plugins/pyloader/src/python_policy.cc b/plugins/pyloader/src/python_policy.cc
index bfea145..97a6b9a 100644
--- a/plugins/pyloader/src/python_policy.cc
+++ b/plugins/pyloader/src/python_policy.cc
@@ -160,27 +160,6 @@ PythonPolicy::get_time_slice() const throw(UserInterruptException)
   return tmp < 0 ? numeric_limits<int>::max() : static_cast<int>(tmp);
 }
 
-policy_sorts_type
-PythonPolicy::wants() const throw(UserInterruptException)
-{
-  PyObject* retval = PyObject_CallMethod(_adapter, "async_wants", NULL);
-  Py_DECREF(retval);
-
-  wait_unlock();
-
-  // Parse return value stored in global Python object
-  retval = PyObject_CallMethod(_adapter, "get_return_value", NULL);
-  assert(retval);
-  long tmp = PyInt_AsLong(retval);
-  Py_DECREF(retval);
-
-  //FIXME add the MalformedPolicyException class and throw it the else
-  // branch instead
-  if(tmp == policy_sorts_threads || tmp == policy_sorts_processes)
-    return static_cast<policy_sorts_type>(tmp);
-  else
-    return policy_sorts_processes;
-}
 
 void
 PythonPolicy::wait_unlock() const throw(UserInterruptException)
diff --git a/plugins/pyloader/src/python_policy.hh b/plugins/pyloader/src/python_policy.hh
index 689fb2d..e0f53f0 100644
--- a/plugins/pyloader/src/python_policy.hh
+++ b/plugins/pyloader/src/python_policy.hh
@@ -76,8 +76,6 @@ namespace sgpem
     */
     int    get_time_slice() const throw(UserInterruptException);
 
-    policy_sorts_type  wants() const throw(UserInterruptException);
-
     void activate()
     {
       //FIXME write code for me
diff --git a/plugins/pyloader/src/sgpem.i b/plugins/pyloader/src/sgpem.i
index 1338d15..1ac60d9 100644
--- a/plugins/pyloader/src/sgpem.i
+++ b/plugins/pyloader/src/sgpem.i
@@ -47,9 +47,6 @@ namespace std {
 
 namespace sgpem {
 
-    /** Don't get worried, order is not important! */
-    enum policy_sorts_type { policy_sorts_threads, policy_sorts_processes };
-
     class Policy {
     public:
 	virtual ~Policy() = 0;
@@ -154,7 +151,7 @@ namespace sgpem {
 				};
 	
 			virtual unsigned int  get_arrival_time() const = 0;
-			virtual unsigned int  get_remaining_time() const = 0;
+			virtual unsigned int  get_elapsed_time() const = 0;
 			virtual int           get_base_priority() const = 0;
 			virtual int           get_current_priority() const = 0;
 			virtual unsigned int  get_total_cpu_time() const = 0;
@@ -198,25 +195,7 @@ namespace sgpem {
 
 			size_t  size() const;
 
-			// Dynamic cast to Process or to Thread so
-			// that Python code sees the extra-methods
-			%typename(out) sgpem::Schedulable*;
-			{
-				// OMG, Ponies!!
-        Process* proc;
-				Thread*  thread;
-        if((proc = dynamic_cast<Process*>($1)) != NULL)
-					$result = SWIG_NewPointerObj(SWIG_as_voidptr(proc), 
-																			 SWIGTYPE_p_sgpem__Process, 0 |  0 );
-        else if((thread = dynamic_cast<Thread*>($1)) != NULL)
-					$result = SWIG_NewPointerObj(SWIG_as_voidptr(thread),
-																			 SWIGTYPE_p_sgpem__Thread, 0 |  0 );
-				else // Fall back to Schedulable* if no dynamic_cast went well:
-					$result = SWIG_NewPointerObj(SWIG_as_voidptr(thread),
-																			 $1_descriptor, 0 |  0 );
-			}
-
-			sgpem::Schedulable* get_item_at(position index);
+			sgpem::Thread* get_item_at(position index);
 
 			%typename(out) sgpem::Schedulable*;
 
diff --git a/src/backend/dynamic_process.cc b/src/backend/dynamic_process.cc
index da6f2e8..1640e26 100644
--- a/src/backend/dynamic_process.cc
+++ b/src/backend/dynamic_process.cc
@@ -155,3 +155,44 @@ DynamicProcess::get_dynamic_threads()
 {
 	return _dynamic_threads;
 }
+
+unsigned int
+DynamicProcess::get_elapsed_time() const
+{
+  unsigned int result = 0;
+  for(std::vector<DynamicThread*>::const_iterator it = _dynamic_threads.begin(); 
+      it != _dynamic_threads.end(); it++)
+    {
+      result += (*it)->get_elapsed_time();
+    }
+  return result;
+}
+
+int
+DynamicProcess::get_last_acquisition() const
+{
+  int result = -1;
+  for(std::vector<DynamicThread*>::const_iterator it = _dynamic_threads.begin(); 
+      it != _dynamic_threads.end(); it++)
+    {
+      int acq = (*it)->get_last_acquisition();
+      if(result < acq) 
+	result = acq;
+    }
+  return result;
+}
+
+int
+DynamicProcess::get_last_release() const
+{
+  int result = -1;
+  for(std::vector<DynamicThread*>::const_iterator it = _dynamic_threads.begin(); 
+      it != _dynamic_threads.end(); it++)
+    {
+      int acq = (*it)->get_last_release();
+      if(result < acq) 
+	result = acq;
+    }
+  return result;
+}
+
diff --git a/src/backend/dynamic_process.hh b/src/backend/dynamic_process.hh
index 69070a0..c7616aa 100644
--- a/src/backend/dynamic_process.hh
+++ b/src/backend/dynamic_process.hh
@@ -53,8 +53,12 @@ namespace sgpem
 
     void serialize(SerializeVisitor& translator) const;
 
-		virtual StaticProcess& get_core();
-		virtual const StaticProcess& get_core() const;
+    int get_last_acquisition() const;
+    int get_last_release() const;
+    unsigned int get_elapsed_time() const;
+
+    virtual StaticProcess& get_core();
+    virtual const StaticProcess& get_core() const;
 
 		// Does also the job of "add_thread" and "remove_thread"
 		std::vector<DynamicThread*>& get_dynamic_threads();
diff --git a/src/backend/dynamic_schedulable.cc b/src/backend/dynamic_schedulable.cc
index 4e6551a..9b7cea1 100644
--- a/src/backend/dynamic_schedulable.cc
+++ b/src/backend/dynamic_schedulable.cc
@@ -28,8 +28,7 @@ using namespace sgpem;
 using namespace std;
 
 DynamicSchedulable::DynamicSchedulable() 
-	: _ran_for(0), _last_acquisition(-1),
-    _last_release(-1), _priority_push(0)
+  :  _priority_push(0)
 {}
 
 bool
@@ -63,60 +62,9 @@ DynamicSchedulable::get_total_cpu_time() const
   return get_core().get_total_cpu_time();
 }
 
-int
-DynamicSchedulable::get_priority_push() const
-{
-  return _priority_push;
-}
-
-int
-DynamicSchedulable::set_priority_push(int new_value)
-{
-	int temp = _priority_push;
-  _priority_push = new_value;
-	return temp;
-}
 
 int
 DynamicSchedulable::get_current_priority() const
 {
   return get_base_priority() + get_priority_push();
 }
-
-unsigned int
-DynamicSchedulable::get_elapsed_time() const
-{
-  return _ran_for;
-}
-
-void
-DynamicSchedulable::decrease_remaining_time()
-{
-  _ran_for++;
-}
-
-int
-DynamicSchedulable::get_last_acquisition() const
-{
-  return _last_acquisition;
-}
-
-void
-DynamicSchedulable::set_last_acquisition(int instant)
-{
-  _last_acquisition = instant;
-}
-
-int
-DynamicSchedulable::get_last_release() const
-{
-  return _last_release;
-}
-
-void
-DynamicSchedulable::set_last_release(int instant)
-{
-  _last_release = instant;
-}
-
-
diff --git a/src/backend/dynamic_schedulable.hh b/src/backend/dynamic_schedulable.hh
index 03c6c1b..12f6986 100644
--- a/src/backend/dynamic_schedulable.hh
+++ b/src/backend/dynamic_schedulable.hh
@@ -68,17 +68,11 @@ namespace sgpem
 
     virtual int get_current_priority() const;
 
-    virtual unsigned int get_elapsed_time() const;
+    virtual unsigned int get_elapsed_time() const = 0;
 
-    virtual void decrease_remaining_time();
+    virtual int get_last_acquisition() const = 0;
 
-    virtual int get_last_acquisition() const;
-
-    virtual void set_last_acquisition(int instant);
-
-    virtual int get_last_release() const;
-
-    virtual void set_last_release(int instant);
+    virtual int get_last_release() const = 0;
 
     /** \brief Returns a pointer to the schedulable object
      *
@@ -89,9 +83,6 @@ namespace sgpem
     virtual const StaticSchedulable& get_core() const = 0;
 
   private:
-    int _ran_for;
-    int _last_acquisition;
-    int _last_release;
     int _priority_push;
   };
 }
diff --git a/src/backend/dynamic_thread.cc b/src/backend/dynamic_thread.cc
index 8de5736..6ed594d 100644
--- a/src/backend/dynamic_thread.cc
+++ b/src/backend/dynamic_thread.cc
@@ -33,7 +33,8 @@ using namespace std;
 
 
 DynamicThread::DynamicThread(StaticThread* core, DynamicProcess* parent) 
-	: DynamicSchedulable(), _core(core), _state(state_future), _parent(parent)
+  : DynamicSchedulable(), _core(core), _state(state_future), _parent(parent),
+    _ran_for(0), _last_acquisition(-1), _last_release(-1)
 {
 	parent->get_threads().push_back(this);
 }
@@ -109,3 +110,41 @@ DynamicThread::get_dynamic_requests()
 {
 	return _dynamic_requests;
 }
+
+
+unsigned int
+DynamicThread::get_elapsed_time() const
+{
+  return _ran_for;
+}
+
+void
+DynamicThread::decrease_remaining_time()
+{
+  _ran_for++;
+}
+
+int
+DynamicThread::get_last_acquisition() const
+{
+  return _last_acquisition;
+}
+
+void
+DynamicThread::set_last_acquisition(int instant)
+{
+  _last_acquisition = instant;
+}
+
+int
+DynamicThread::get_last_release() const
+{
+  return _last_release;
+}
+
+void
+DynamicThread::set_last_release(int instant)
+{
+  _last_release = instant;
+}
+
diff --git a/src/backend/dynamic_thread.hh b/src/backend/dynamic_thread.hh
index 7a1d221..5aef98c 100644
--- a/src/backend/dynamic_thread.hh
+++ b/src/backend/dynamic_thread.hh
@@ -50,9 +50,17 @@ namespace sgpem
     DynamicProcess& get_process();
 
     state get_state() const;
-
     state set_state(state new_state);
 
+    int get_last_acquisition() const;
+    void set_last_acquisition(int instant);
+
+    int get_last_release() const;
+    void set_last_release(int instant);
+
+    unsigned int get_elapsed_time() const;
+    void decrease_remaining_time();
+
     std::vector<Request*> get_requests();
 
     void serialize(SerializeVisitor& translator) const;
@@ -68,6 +76,10 @@ namespace sgpem
     state _state;
     std::vector<DynamicRequest*> _dynamic_requests;
     DynamicProcess* _parent;
+
+    int _ran_for;
+    int _last_acquisition;
+    int _last_release;
   };
 
 }
diff --git a/src/backend/policy.cc b/src/backend/policy.cc
index 3315676..6980191 100644
--- a/src/backend/policy.cc
+++ b/src/backend/policy.cc
@@ -25,12 +25,6 @@ using namespace sgpem;
 Policy::~Policy()
 {}
 
-int
-Policy::get_id() const
-{
-  return _id;
-}
-
 
 PolicyParameters&
 Policy::get_parameters()
diff --git a/src/backend/policy.hh b/src/backend/policy.hh
index 9fb0c0f..61e3bc8 100644
--- a/src/backend/policy.hh
+++ b/src/backend/policy.hh
@@ -32,13 +32,6 @@
 
 namespace sgpem
 {
-
-  enum policy_sorts_type
-  {
-    policy_sorts_threads,
-    policy_sorts_processes
-  };
-
   class Policy;
 
   /** \brief
@@ -50,7 +43,6 @@ namespace sgpem
   class SG_DLLEXPORT Policy
   {
   public:
-
     virtual ~Policy();
 
     /**
@@ -70,12 +62,6 @@ namespace sgpem
      */
     virtual void sort_queue() const throw(UserInterruptException) = 0;
 
-    /**
-      Gets the unique identifier (id) of this Policy.
-      \return The Policy id.
-     */
-    int get_id() const;
-
     /**
       Gets a string description of the policy.
 
@@ -105,16 +91,6 @@ namespace sgpem
      */
     virtual int get_time_slice() const throw(UserInterruptException) = 0;
 
-    /**
-      Tell what kind of entities are scheduled by this policy.
-
-      Because it's a pure virtual method, must be re-implemented 
-      in concrete derived classes.
-      \return A SortsType value identifying the desired type for the objects
-       composing the queue passed to the sort_queue method.
-     */
-    virtual policy_sorts_type wants() const throw(UserInterruptException) = 0;
-
     virtual void activate() = 0;
 
     virtual void deactivate() = 0;
@@ -130,7 +106,6 @@ namespace sgpem
 
   protected:
     PolicyParameters _parameters;
-    int   _id;
   };
 
 }//~ namespace sgpem
diff --git a/src/backend/ready_queue.cc b/src/backend/ready_queue.cc
index bbae6ab..fd91f89 100644
--- a/src/backend/ready_queue.cc
+++ b/src/backend/ready_queue.cc
@@ -36,7 +36,7 @@ ReadyQueue::swap(position a, position b)
 	// Once we've done the check once, we
 	// can assume it's safe to use "[]";
 	// this for performance reasons.
-	Schedulable* temp = _scheds.at(a);
+	Thread* temp = _scheds.at(a);
 	_scheds[a] = _scheds.at(b);
 	_scheds[b] = temp;
 }
@@ -49,7 +49,7 @@ ReadyQueue::size() const
 }
 
 
-sgpem::Schedulable&
+sgpem::Thread&
 ReadyQueue::get_item_at(position index)
 	throw (std::out_of_range)
 {
@@ -59,7 +59,7 @@ ReadyQueue::get_item_at(position index)
 
 
 void
-ReadyQueue::append(Schedulable& schedulable)
+ReadyQueue::append(Thread& thread)
 {
-	_scheds.push_back(&schedulable);
+	_scheds.push_back(&thread);
 }
diff --git a/src/backend/ready_queue.hh b/src/backend/ready_queue.hh
index 50ad424..69fc3b4 100644
--- a/src/backend/ready_queue.hh
+++ b/src/backend/ready_queue.hh
@@ -29,7 +29,7 @@
 namespace sgpem
 {
 	class ReadyQueue;
-	class Schedulable;
+	class Thread;
 
   class SG_DLLEXPORT ReadyQueue
   {
@@ -37,14 +37,14 @@ namespace sgpem
 		typedef unsigned int position;
 		typedef unsigned int size_t;
 
-		void          swap(position a, position b) throw (std::out_of_range);
-		size_t        size() const;
-		Schedulable&  get_item_at(position index) throw (std::out_of_range);
-		void          append(Schedulable& schedulable);
-
-	private:
-		typedef std::vector<Schedulable*> Schedulables;
-		Schedulables _scheds;
+		void       swap(position a, position b) throw (std::out_of_range);
+		size_t     size() const;
+		Thread&    get_item_at(position index) throw (std::out_of_range);
+		void       append(Thread& schedulable);
+		
+  private:
+		typedef std::vector<Thread*> Threads;
+		Threads _scheds;
   };
 
 }
diff --git a/src/backend/scheduler.cc b/src/backend/scheduler.cc
index ef3839d..07125c8 100644
--- a/src/backend/scheduler.cc
+++ b/src/backend/scheduler.cc
@@ -182,10 +182,7 @@ Scheduler::step_forward(History& history, Policy& cpu_policy) throw(UserInterrup
   // should maybe be done here as the first thing, instead than 
   // directly when selecting them
   if(running_thread != NULL)
-    {
       running_thread->decrease_remaining_time();
-      running_thread->get_process().decrease_remaining_time();
-    }
   
   // 4a. Requests for the running thread exhausted
   if(running_thread != NULL) {