diff --git a/hwcompatible/compatibility.py b/hwcompatible/compatibility.py
index 9ddd2706aff8066c8bfdd58574ec13e112cec6c3..01e91559590e48ac12cabfb462e741726e095b7f 100755
--- a/hwcompatible/compatibility.py
+++ b/hwcompatible/compatibility.py
@@ -442,7 +442,7 @@ class EulerCertification(object):
 
     def update_factory(self, test_factory):
         """
-        update teset factory
+        update tese factory
         :param test_factory:
         :return:
         """
diff --git a/hwcompatible/document.py b/hwcompatible/document.py
index 5584ec3507e02e036055a984dc074429f214c065..8d86f888f25ffef8b7226c1b9aa7485f944f797e 100755
--- a/hwcompatible/document.py
+++ b/hwcompatible/document.py
@@ -21,7 +21,10 @@ from .sysinfo import SysInfo
 from .env import CertEnv
 
 
-class Document:
+class Document(object):
+    """
+    Read and write documents
+    """
     def __init__(self, filename, document=''):
         self.document = document
         self.filename = filename
@@ -51,6 +54,9 @@ class Document:
 
 
 class CertDocument(Document):
+    """
+    get hardware and release information
+    """
     def __init__(self, filename, document=''):
         super(CertDocument, self).__init__(filename, document)
         self.document = dict()
@@ -107,6 +113,9 @@ class CertDocument(Document):
 
 
 class DeviceDocument(Document):
+    """
+    get device document
+    """
     def __init__(self, filename, devices=''):
         super(DeviceDocument, self).__init__(filename, devices)
         self.filename = filename
@@ -119,6 +128,10 @@ class DeviceDocument(Document):
 
 
 class FactoryDocument(Document):
+    """
+    get factory from file or factory parameter
+    """
+
     def __init__(self, filename, factory=''):
         super(FactoryDocument, self).__init__(filename, factory)
         self.document = list()
@@ -147,9 +160,11 @@ class FactoryDocument(Document):
         return factory
 
 
-class ConfigFile:
+class ConfigFile(object):
+    """
+    Get parameters from configuration file
+    """
     def __init__(self, filename):
-        super(ConfigFile, self).__init__(filename)
         self.filename = filename
         self.parameters = dict()
         self.config = list()
diff --git a/hwcompatible/sysinfo.py b/hwcompatible/sysinfo.py
index d5c5dcd9124175384c8cbc538e04478585d70d65..e7bae13891e970357bead5ac15505f47c67c19f9 100755
--- a/hwcompatible/sysinfo.py
+++ b/hwcompatible/sysinfo.py
@@ -16,7 +16,10 @@ import os
 import re
 
 
-class SysInfo:
+class SysInfo(object):
+    """
+    Get system information
+    """
     def __init__(self, filename):
         self.product = None
         self.version = None