diff --git a/src/add_request_dialog.cc b/src/add_request_dialog.cc
index ecfa5cf..b3c8077 100644
--- a/src/add_request_dialog.cc
+++ b/src/add_request_dialog.cc
@@ -38,6 +38,7 @@ using namespace sgpem;
 using namespace Gtk;
 using namespace Glib;
 using Gnome::Glade::Xml;
+using std::vector;
 
 AddRequestDialog::AddRequestDialog(BaseObjectType* cobject, const RefPtr<Xml>& glade) :
   Dialog(cobject), _glade(glade)
@@ -47,6 +48,9 @@ AddRequestDialog::AddRequestDialog(BaseObjectType* cobject, const RefPtr<Xml>& g
   _glade->get_widget("Remove", _remove_button);
   _glade->get_widget("Resource.Combo", _resource_combo);
   _glade->get_widget("OK.Button", _ok_button);
+  _glade->get_widget("Instant.Spin", _instant_spin);
+  _glade->get_widget("Duration.Spin", _duration_spin);
+
 
   /** ATTACH SIGNAL HANDLERS FOR BUTTONS **/
   
@@ -95,31 +99,89 @@ AddRequestDialog::AddRequestDialog(BaseObjectType* cobject, const RefPtr<Xml>& g
       sigc::mem_fun(*this, &AddRequestDialog::_on_list_selection_changed));
 }
 
-Request&
-AddRequestDialog::construct_request(Thread& owner)
+Request*
+AddRequestDialog::run_add(Thread& owner)
 {
-  assert(_list_model->children());
+  update_combo();
 
-  SpinButton* instant_spin;
-  _glade->get_widget("Instant.Spin", instant_spin);
-
-  History& h = Simulation::get_instance().get_history();
+  Request* r = NULL;
   
-  Request& r = h.add_request(owner, instant_spin->get_value_as_int());
-
-  TreeNodeChildren sreq_container = _list_model->children();
+  // reset the dialog data
+  _list_model->clear();
+  _instant_spin->set_value(0.0);
+  _duration_spin->set_value(0.0);
   
-  for(Iseq<TreeIter> it = iseq(sreq_container); it; ++it)
-    h.add_subrequest(r, (*it)[_list_key_column], (*it)[_list_length_column]);
+  if(run() == RESPONSE_OK)
+  {
+    assert(_list_model->children());
+
+    History& h = Simulation::get_instance().get_history();
+
+    r = &h.add_request(owner, _instant_spin->get_value_as_int());
+
+    TreeNodeChildren sreq_container = _list_model->children();
+
+    for(Iseq<TreeIter> it = iseq(sreq_container); it; ++it)
+      h.add_subrequest(*r, (*it)[_list_key_column], (*it)[_list_length_column]);
+  }
+
+  hide();
 
   return r;
 }
 
 void
-AddRequestDialog::on_show()
+AddRequestDialog::run_edit(Request& request)
 {
-  //TODO is this a reasonable place where to fill the combo model?
+  update_combo();
+
+  _list_model->clear();
+
+  History& history = Simulation::get_instance().get_history();
+  const Environment::Resources& resources = history.get_last_environment().get_resources();
   
+  _instant_spin->set_value(static_cast<double>(request.get_instant()));
+  
+  // PLEASE KEEP THIS A COPY, WE *NEED* TO COPY IT
+  vector<SubRequest*> subrequests = request.get_subrequests();
+
+  for(Iseq<vector<SubRequest*>::iterator> it = iseq(subrequests); it; ++it)
+  {
+    SubRequest& sr = *(*it);
+
+    TreeModel::Row row = *(_list_model->append());
+
+    unsigned int key = sr.get_resource_key();
+    row[_list_key_column] = key;
+
+    const ustring name = resources.find(key)->second->get_name();
+    row[_list_resource_column] = name;
+
+    row[_list_length_column] = sr.get_length();
+  }
+
+  if(run() == RESPONSE_OK)
+  {
+    assert(_list_model->children());
+
+    // I know it's a bit hack-ish, but do you know an elegant alternative way?
+    for(Iseq<vector<SubRequest*>::iterator> it = iseq(subrequests); it; ++it)
+      history.remove(*(*it));
+
+    history.edit_request(request, _instant_spin->get_value_as_int());
+
+    TreeNodeChildren sreq_container = _list_model->children();
+
+    for(Iseq<TreeIter> it = iseq(sreq_container); it; ++it)
+      history.add_subrequest(request, (*it)[_list_key_column], (*it)[_list_length_column]);
+  }
+
+  hide();
+}
+
+void
+AddRequestDialog::update_combo()
+{
   typedef Environment::Resources::const_iterator ResourceIt;
   
   const Environment::Resources& resources = 
@@ -142,10 +204,6 @@ AddRequestDialog::_on_add()
 {
   TreeModel::iterator sel = _resource_combo->get_active();
 
-  SpinButton* duration_spin;
-
-  _glade->get_widget("Duration.Spin", duration_spin);
-
   TreeModel::Row row = *(_list_model->append());
 
   const unsigned int key = (*sel)[_combo_key_column];
@@ -154,7 +212,7 @@ AddRequestDialog::_on_add()
   const ustring resource = (*sel)[_combo_resource_column];
   row[_list_resource_column] = resource;
 
-  const unsigned int length = duration_spin->get_value_as_int();
+  const unsigned int length = _duration_spin->get_value_as_int();
   row[_list_length_column] = length;
 }
 
diff --git a/src/add_request_dialog.hh b/src/add_request_dialog.hh
index b9d6b54..b68b609 100644
--- a/src/add_request_dialog.hh
+++ b/src/add_request_dialog.hh
@@ -33,6 +33,7 @@ namespace sgpem
 #include <gtkmm/liststore.h>
 #include <gtkmm/dialog.h>
 #include <gtkmm/combobox.h>
+#include <gtkmm/spinbutton.h>
 #include <libglademm/xml.h>
 
 namespace sgpem
@@ -43,17 +44,21 @@ namespace sgpem
     AddRequestDialog(BaseObjectType* cobject, const Glib::RefPtr<Gnome::Glade::Xml>& glade);
 
     /** 
-      \brief Attemts to build a request by using the data supplied 
-      up to now. 
-      \note Must be called only after it has been shown at least
-      one time with an OK, otherwise expect undefined behaviour!
+      \brief Attemts to show the dialog, and constructs a request 
+      if response is OK 
+      \param owner The thread which will own the request
       */
-    Request& construct_request(Thread& t);
-
-  protected:
-    virtual void on_show();
-
+    Request* run_add(Thread& owner);
+    
+    /** 
+      \brief Attemts to show the dialog, and modify an existing request 
+      if response is OK 
+      \param resource The request to modify
+      */
+    void run_edit(Request& resource);
+    
   private:
+    void update_combo();
     void _on_add();
     void _on_remove();
     void _on_list_selection_changed();
@@ -72,6 +77,8 @@ namespace sgpem
     Gtk::Button* _add_button;
     Gtk::Button* _remove_button;
     Gtk::Button* _ok_button;
+    Gtk::SpinButton* _instant_spin;
+    Gtk::SpinButton* _duration_spin;
 
     Gtk::ComboBox* _resource_combo;
     Glib::RefPtr<Gtk::ListStore> _combo_model;
diff --git a/src/schedulables_tree_widget.cc b/src/schedulables_tree_widget.cc
index 1db0f12..38e6f61 100644
--- a/src/schedulables_tree_widget.cc
+++ b/src/schedulables_tree_widget.cc
@@ -185,6 +185,15 @@ SchedulablesTreeWidget::on_button_press_event(GdkEventButton* event)
     
     action_group->add( Gtk::Action::create("AddRequest", "Add Request"),
 	sigc::mem_fun(*this, &SchedulablesTreeWidget::_on_add_request) );
+
+    action_group->add( Gtk::Action::create("EditProcess", "Edit Process"),
+	sigc::mem_fun(*this, &SchedulablesTreeWidget::_on_edit_process) );
+    
+    action_group->add( Gtk::Action::create("EditThread", "Edit Thread"),
+        sigc::mem_fun(*this, &SchedulablesTreeWidget::_on_edit_thread) );
+    
+    action_group->add( Gtk::Action::create("EditRequest", "Edit Request"),
+        sigc::mem_fun(*this, &SchedulablesTreeWidget::_on_edit_request) );
     
     action_group->add( Gtk::Action::create("RemoveProcess", "Remove Process"),
 	sigc::mem_fun(*this, &SchedulablesTreeWidget::_on_remove_process) );
@@ -203,43 +212,42 @@ SchedulablesTreeWidget::on_button_press_event(GdkEventButton* event)
 
     const HandleType selection_type = get_selection_type();
     
-    Glib::ustring ui_info = 
-	  "<ui>"
-	  "  <popup name='PopupMenu'>";
-
-    if(selection_type == htype_process)
-      ui_info +=    
-          "    <menuitem action='AddThread'/>";
-    else if(selection_type == htype_thread)
-      ui_info +=      
-	  "    <menuitem action='AddRequest'/>";
-    
-    ui_info +=
-	  "    <menuitem action='AddProcess'/>";
+    Glib::ustring adds;
+    Glib::ustring edits;
+    Glib::ustring removes;
+    Glib::ustring separator;
     
     if(selection_type != htype_undefined)
-      ui_info +=
-	  "    <separator/>";
+      separator = "<separator/>";
     
     switch(selection_type)
     {
     case htype_process:
-      ui_info += 
-	  "    <menuitem action='RemoveProcess'/>";
+      adds = "<menuitem action='AddThread'/>";
+      edits = "<menuitem action='EditProcess'/>";
+      removes = "<menuitem action='RemoveProcess'/>";
       break;
     case htype_thread:
-      ui_info += 
-	  "    <menuitem action='RemoveThread'/>";
+      adds = "<menuitem action='AddRequest'/>";
+      edits = "<menuitem action='EditThread'/>";
+      removes = "<menuitem action='RemoveThread'/>";
       break;
     case htype_request:
-      ui_info += 
-	  "    <menuitem action='RemoveRequest'/>";
+      edits = "<menuitem action='EditRequest'/>";
+      removes = "<menuitem action='RemoveRequest'/>";
       break;
     case htype_subrequest:
-      ui_info += 
-	  "    <menuitem action='RemoveSubrequest'/>";
+      removes = "<menuitem action='RemoveSubrequest'/>";
     }
+
+    adds += "<menuitem action='AddProcess'/>";
     
+    Glib::ustring ui_info = 
+	  "<ui>"
+	  "  <popup name='PopupMenu'>";
+
+    ui_info += adds + separator + edits + ((edits.size() == 0) ? ustring() : separator) + removes;
+
     ui_info +=
           "  </popup>"
 	  "</ui>";
@@ -327,19 +335,63 @@ SchedulablesTreeWidget::update(const History& history)
 void
 SchedulablesTreeWidget::_on_add_process()
 {
+  add_edit_process(true);
+}
+
+void
+SchedulablesTreeWidget::_on_edit_process()
+{
+  add_edit_process(false);
+}
+
+void
+SchedulablesTreeWidget::add_edit_process(bool adding)
+{
+  /** This is ugly, I know, we should be using derived widgets, but I also believe we 
+   * have little time, and I'm not going to waste too much of it on the frontend */
+  
+  Entry* name_entry;
+  SpinButton* arrival_time_spin;
+  SpinButton* base_priority_spin;
+
+  _add_process_dialog_glade->get_widget("Name.Entry", name_entry);
+  _add_process_dialog_glade->get_widget("ArrivalTime.Spin", arrival_time_spin);
+  _add_process_dialog_glade->get_widget("BasePriority.Spin", base_priority_spin);
+ 
+  Process* selection = NULL;
+  
+  if(!adding)
+  {
+    selection = get_selected<Process>();
+
+    name_entry->set_text(selection->get_name());
+    arrival_time_spin->set_value(static_cast<double>(selection->get_arrival_time()));
+    base_priority_spin->set_value(static_cast<double>(selection->get_base_priority()));
+  }
+  else
+  {
+    name_entry->set_text("");
+    arrival_time_spin->set_value(0.0);
+    base_priority_spin->set_value(0.0);
+  }
+
+  
   if(_add_process_dialog->run() == RESPONSE_OK)
   {
-    Entry* name_entry;
-    SpinButton* arrival_time_spin;
-    SpinButton* base_priority_spin;
     
-    _add_process_dialog_glade->get_widget("Name.Entry", name_entry);
-    _add_process_dialog_glade->get_widget("ArrivalTime.Spin", arrival_time_spin);
-    _add_process_dialog_glade->get_widget("BasePriority.Spin", base_priority_spin);
-
-    Simulation::get_instance().get_history().add_process(name_entry->get_text(), 
-                                                         arrival_time_spin->get_value_as_int(), 
-							 base_priority_spin->get_value_as_int());
+    if(adding)
+    {
+      Simulation::get_instance().get_history().add_process(name_entry->get_text(), 
+                                                           arrival_time_spin->get_value_as_int(), 
+                                                           base_priority_spin->get_value_as_int());
+    }
+    else
+    {
+      Simulation::get_instance().get_history().edit_process(*selection,
+                                                            name_entry->get_text(), 
+                                                            arrival_time_spin->get_value_as_int(), 
+                                                            base_priority_spin->get_value_as_int()); 
+    }
   }
   
   _add_process_dialog->hide();
@@ -348,27 +400,74 @@ SchedulablesTreeWidget::_on_add_process()
 void
 SchedulablesTreeWidget::_on_add_thread()
 {  
-  Process* p = get_selected<Process>();
-  if(p == NULL)
-    return;
+  add_edit_thread(true);
+}
+
+void
+SchedulablesTreeWidget::_on_edit_thread()
+{
+  add_edit_thread(false);
+}
+
+void
+SchedulablesTreeWidget::add_edit_thread(bool adding)
+{
+  /** This is ugly, I know, we should be using derived widgets, but I also believe we 
+   * have little time, and I'm not going to waste too much of it on the frontend */
+  
+  Entry* name_entry;
+  SpinButton* cpu_time_spin;
+  SpinButton* arrival_time_spin;
+  SpinButton* base_priority_spin;
+
+  _add_thread_dialog_glade->get_widget("Name.Entry", name_entry);
+  _add_thread_dialog_glade->get_widget("CpuTime.Spin", cpu_time_spin);
+  _add_thread_dialog_glade->get_widget("ArrivalTime.Spin", arrival_time_spin);
+  _add_thread_dialog_glade->get_widget("BasePriority.Spin", base_priority_spin);
+
+  Thread* t = NULL;
+  
+  if(!adding)
+  {
+    t = get_selected<Thread>();
+    
+    name_entry->set_text(t->get_name());
+    cpu_time_spin->set_value(static_cast<double>(t->get_total_cpu_time()));
+    arrival_time_spin->set_value(static_cast<double>(t->get_arrival_time()));
+    base_priority_spin->set_value(static_cast<double>(t->get_base_priority()));
+  }
+  else
+  {
+    name_entry->set_text("");
+    cpu_time_spin->set_value(1.0);
+    arrival_time_spin->set_value(0.0);
+    base_priority_spin->set_value(0.0);
+  }
+
   
   if(_add_thread_dialog->run() == RESPONSE_OK)
   {
-    Entry* name_entry;
-    SpinButton* cpu_time_spin;
-    SpinButton* arrival_time_spin;
-    SpinButton* base_priority_spin;
-    
-    _add_thread_dialog_glade->get_widget("Name.Entry", name_entry);
-    _add_thread_dialog_glade->get_widget("CpuTime.Spin", cpu_time_spin);
-    _add_thread_dialog_glade->get_widget("ArrivalTime.Spin", arrival_time_spin);
-    _add_thread_dialog_glade->get_widget("BasePriority.Spin", base_priority_spin);
 
-    Simulation::get_instance().get_history().add_thread(name_entry->get_text(),
-							*p, 
-							cpu_time_spin->get_value_as_int(),
-							arrival_time_spin->get_value_as_int(), 
-							base_priority_spin->get_value_as_int());
+    if(adding)
+    {
+      Process* p = get_selected<Process>();
+      assert(p != NULL);
+	  
+      Simulation::get_instance().get_history().add_thread(name_entry->get_text(),
+							  *p, 
+							  cpu_time_spin->get_value_as_int(),
+							  arrival_time_spin->get_value_as_int(), 
+							  base_priority_spin->get_value_as_int());
+    }
+    else
+    {
+      Simulation::get_instance().get_history().edit_thread(*t,
+                                                          name_entry->get_text(),
+							  cpu_time_spin->get_value_as_int(),
+							  arrival_time_spin->get_value_as_int(), 
+							  base_priority_spin->get_value_as_int());
+
+    }
     
   }
   
@@ -380,13 +479,19 @@ SchedulablesTreeWidget::_on_add_request()
 {  
   Thread* t = get_selected<Thread>();
 
-  if(t == NULL)
-    return;
-
-  if(_add_request_dialog->run() == RESPONSE_OK)
-    _add_request_dialog->construct_request(*t);
+  assert(t != NULL);
   
-  _add_request_dialog->hide();
+  _add_request_dialog->run_add(*t);
+}
+
+void
+SchedulablesTreeWidget::_on_edit_request()
+{  
+  Request* r = get_selected<Request>();
+
+  assert(r != NULL);
+  
+  _add_request_dialog->run_edit(*r);
 }
 
 void
diff --git a/src/schedulables_tree_widget.hh b/src/schedulables_tree_widget.hh
index 2df1d37..a9b8581 100644
--- a/src/schedulables_tree_widget.hh
+++ b/src/schedulables_tree_widget.hh
@@ -88,6 +88,13 @@ namespace sgpem
     void _on_add_thread();
     void _on_add_request();
 
+    void _on_edit_process();
+    void _on_edit_thread();
+    void _on_edit_request();
+
+    void add_edit_process(bool adding);
+    void add_edit_thread(bool adding);
+    
     void _on_remove_process();
     void _on_remove_thread();
     void _on_remove_request();