diff --git a/ActFrame.py b/ActFrame.py
new file mode 100644
index 0000000..14e0ab5
--- /dev/null
+++ b/ActFrame.py
@@ -0,0 +1,34 @@
+from abc import ABC, abstractmethod
+
+
+class ActFrame(ABC):
+
+    def __init__(self, actType, actParams = None):
+        if actType == None:
+            raise Exception('actType cannot be None')
+        self.__actType = actType
+
+        if actParams != None:
+            if type(actParams) is not list:
+                raise Exception(
+                    'actParams has wrong type: expected type \'list\', got \'{}\''.format(type(actParams)))
+            self.__actParams = actParams
+
+    def __repr__(self):
+        return str(type(self))
+
+    def __str__(self):
+        return "actType:{} actParams:{}".format(self.__actType,self.__actParams)
+
+
+    def setActParams(self, actParams):
+        if type(actParams) is not list:
+            raise Exception(
+                'actParams has wrong type: expected type \'list\', got \'{}\''.format(type(actParams)))
+        self.__actParams = actParams
+
+    def getActParams(self):
+        return self.__actParams
+
+    def getActType(self):
+        return self.__actType
diff --git a/DialoguePolicy.py b/DialoguePolicy.py
index 5f539a5..da76f96 100644
--- a/DialoguePolicy.py
+++ b/DialoguePolicy.py
@@ -1,5 +1,6 @@
+from SystemAct import SystemAct
 from UserActType import UserActType
-from UserAct import UserAct
+from SystemActType import SystemActType
 
 
 class DP:
@@ -12,13 +13,15 @@ class DP:
     def __init__(self):
         pass
 
-    def chooseTactic(self, frameList=None):
-        if frameList[-1].getActType() is UserActType.INVALID:
-            systemAct = [1]
-            return systemAct
-        elif frameList[-1].getActType() is UserActType.BYE:
-            systemAct = [2]
-            return systemAct
-        else:
-            systemAct = [0]
-            return systemAct
+    def chooseTactic(self, frameList=None) -> SystemAct:
+        userAct = frameList[-1]
+        if userAct.getActType() == UserActType.WELCOME_MSG:
+            return  SystemAct(SystemActType.WELCOME_MSG)
+        if userAct.getActType() == UserActType.REQUEST:
+            if "name" in userAct.getActParams():
+                return SystemAct(SystemActType.INFORM,['name'])
+        if userAct.getActType() == UserActType.BYE:
+            return SystemAct(SystemActType.BYE)
+        if userAct.getActType() == UserActType.INVALID:
+            return SystemAct(SystemActType.NOT_UNDERSTOOD)
+        raise Exception("UserAct:{} not recognized".format(userAct))
diff --git a/NaturalLAnguageGeneration.py b/NaturalLAnguageGeneration.py
index e60f8a5..6e3e1fa 100644
--- a/NaturalLAnguageGeneration.py
+++ b/NaturalLAnguageGeneration.py
@@ -1,3 +1,6 @@
+from SystemAct import SystemAct
+from SystemActType import SystemActType
+
 class NLG:
     """
     Moduł, który tworzy reprezentację tekstową aktu systemowego wybranego przez taktykę dialogu.
@@ -8,10 +11,14 @@ class NLG:
     def __init__(self):
         pass
 
-    def toText(self, systemAct):
-        if systemAct == [1]:
-            return "Nie rozumiem o czym mówisz."
-        if systemAct == [2]:
+    def toText(self, systemAct: SystemAct) -> str:
+        if systemAct.getActType() == SystemActType.WELCOME_MSG:
+            return "Cześć"
+        if systemAct.getActType() == SystemActType.INFORM:
+            if "name" in systemAct.getActParams():
+                return "Nazywam się Janusz"
+        if systemAct.getActType() == SystemActType.BYE:
             return "Do widzenia."
-        else:
-            return "Witaj, nazywam się Janusz."
+        if systemAct.getActType() == SystemActType.NOT_UNDERSTOOD:
+            return "Nie rozumiem o czym mówisz."
+        raise Exception("SystemAct:{} not recognized".format(systemAct))
diff --git a/NaturalLanguageUnderstanding.py b/NaturalLanguageUnderstanding.py
index 1863824..f84992a 100644
--- a/NaturalLanguageUnderstanding.py
+++ b/NaturalLanguageUnderstanding.py
@@ -29,7 +29,7 @@ class NLU:
             )
         ]
 
-    def parseUserInput(self, text):
+    def parseUserInput(self, text: str) -> UserAct:
         for pattern, actType, actParams in self.__actParsePatternList:
             regex = re.compile(pattern, re.IGNORECASE)
             match = regex.match(text)
diff --git a/SystemAct.py b/SystemAct.py
new file mode 100644
index 0000000..eb7d150
--- /dev/null
+++ b/SystemAct.py
@@ -0,0 +1,12 @@
+from SystemActType import SystemActType
+from ActFrame import ActFrame
+
+class SystemAct(ActFrame):
+    def __init__(self, actType, actParams = None):
+        if actType != None and type(actType) is not SystemActType:
+            raise Exception('actParams has wrong type: expected type {}, got {}'.format(type(SystemActType.WELCOME_MSG), type(actType)))
+
+        super(SystemAct, self).__init__(actType, actParams)
+
+    def isDialogFinished(self):
+        return self.getActType() == SystemActType.BYE
diff --git a/SystemActType.py b/SystemActType.py
new file mode 100644
index 0000000..338090d
--- /dev/null
+++ b/SystemActType.py
@@ -0,0 +1,9 @@
+from enum import Enum, unique
+
+
+@unique
+class SystemActType(Enum):
+    WELCOME_MSG = 0
+    INFORM = 1
+    BYE = 2
+    NOT_UNDERSTOOD = -1
diff --git a/UserAct.py b/UserAct.py
index 722b1bf..e644dd4 100644
--- a/UserAct.py
+++ b/UserAct.py
@@ -1,32 +1,9 @@
 from UserActType import UserActType
+from ActFrame import ActFrame
 
-
-class UserAct:
+class UserAct(ActFrame):
     def __init__(self, actType, actParams = None):
-        if actType == None:
-            raise Exception('actType cannot be None')
-        self.__actType = actType
+        if actType != None and type(actType) is not UserActType:
+            raise Exception('actParams has wrong type: expected type {}, got {}'.format(type(UserActType.WELCOME_MSG), type(actType)))
 
-        if actParams != None:
-            if type(actParams) is not list:
-                raise Exception(
-                    'actParams has wrong type: expected type \'list\', got \'{}\''.format(type(actParams)))
-            self.__actParams = actParams
-
-    def __repr__(self):
-        return "UserAct()"
-
-    def __str__(self):
-        return "actType:{} actParams:{}".format(self.__actType,self.__actParams)
-
-    def setActParams(self, actParams):
-        if type(actParams) is not list:
-            raise Exception(
-                'actParams has wrong type: expected type \'list\', got \'{}\''.format(type(actParams)))
-        self.__actParams = actParams
-
-    def getActParams(self):
-        return self.__actParams
-
-    def getActType(self):
-        return self.__actType
+        super(UserAct, self).__init__(actType, actParams)
\ No newline at end of file
diff --git a/main.py b/main.py
index 09d7074..9391992 100644
--- a/main.py
+++ b/main.py
@@ -19,5 +19,5 @@ if __name__ == "__main__":
         text = nlg.toText(system_act)
 
         print(text)
-        if text == "Do widzenia.":
+        if system_act.isDialogFinished():
             break