diff --git a/tempest/common/generator/base_generator.py b/tempest/common/generator/base_generator.py
index 0398af1..ae4e743 100644
--- a/tempest/common/generator/base_generator.py
+++ b/tempest/common/generator/base_generator.py
@@ -13,6 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import copy
 import functools
 
 import jsonschema
@@ -30,9 +31,11 @@
     return expected_result
 
 
-def generator_type(*args):
+def generator_type(*args, **kwargs):
     def wrapper(func):
         func.types = args
+        for key in kwargs:
+            setattr(func, key, kwargs[key])
         return func
     return wrapper
 
@@ -106,37 +109,71 @@
             jsonschema.Draft4Validator.check_schema(schema['json-schema'])
         jsonschema.validate(schema, self.schema)
 
-    def generate(self, schema):
+    def generate_scenarios(self, schema, path=None):
         """
-        Generate an json dictionary based on a schema.
-        Only one value is mis-generated for each dictionary created.
+        Generates the scenario (all possible test cases) out of the given
+        schema.
 
-        Any generator must return a list of tuples or a single tuple.
-        The values of this tuple are:
-          result[0]: Name of the test
-          result[1]: json schema for the test
-          result[2]: expected result of the test (can be None)
+        :param schema: a dict style schema (see ``BasicGeneratorSet.schema``)
+        :param path: the schema path if the given schema is a subschema
         """
-        LOG.debug("generate_invalid: %s" % schema)
-        schema_type = schema["type"]
-        if isinstance(schema_type, list):
+        schema_type = schema['type']
+        scenarios = []
+
+        if schema_type == 'object':
+            properties = schema["properties"]
+            for attribute, definition in properties.iteritems():
+                current_path = copy.copy(path)
+                if path is not None:
+                    current_path.append(attribute)
+                else:
+                    current_path = [attribute]
+                scenarios.extend(
+                    self.generate_scenarios(definition, current_path))
+        elif isinstance(schema_type, list):
             if "integer" in schema_type:
                 schema_type = "integer"
             else:
                 raise Exception("non-integer list types not supported")
-        result = []
-        if schema_type not in self.types_dict:
-            raise TypeError("generator (%s) doesn't support type: %s"
-                            % (self.__class__.__name__, schema_type))
         for generator in self.types_dict[schema_type]:
-            ret = generator(schema)
-            if ret is not None:
-                if isinstance(ret, list):
-                    result.extend(ret)
-                elif isinstance(ret, tuple):
-                    result.append(ret)
-                else:
-                    raise Exception("generator (%s) returns invalid result: %s"
-                                    % (generator, ret))
-        LOG.debug("result: %s" % result)
-        return result
+            if hasattr(generator, "needed_property"):
+                prop = generator.needed_property
+                if (prop not in schema or
+                    schema[prop] is None or
+                    schema[prop] is False):
+                    continue
+
+            name = generator.__name__
+            if path is not None:
+                name = "%s_%s" % ("_".join(path), name)
+            scenarios.append({
+                "_negtest_name": name,
+                "_negtest_generator": generator,
+                "_negtest_schema": schema,
+                "_negtest_path": path})
+        return scenarios
+
+    def generate_payload(self, test, schema):
+        """
+        Generates one jsonschema out of the given test. It's mandatory to use
+        generate_scenarios before to register all needed variables to the test.
+
+        :param test: A test object (scenario) with all _negtest variables on it
+        :param schema: schema for the test
+        """
+        generator = test._negtest_generator
+        ret = generator(test._negtest_schema)
+        path = copy.copy(test._negtest_path)
+        expected_result = None
+
+        if ret is not None:
+            generator_result = generator(test._negtest_schema)
+            invalid_snippet = generator_result[1]
+            expected_result = generator_result[2]
+            element = path.pop()
+            if len(path) > 0:
+                schema_snip = reduce(dict.get, path, schema)
+                schema_snip[element] = invalid_snippet
+            else:
+                schema[element] = invalid_snippet
+        return expected_result
diff --git a/tempest/common/generator/negative_generator.py b/tempest/common/generator/negative_generator.py
index 4f3d2cd..1d5ed43 100644
--- a/tempest/common/generator/negative_generator.py
+++ b/tempest/common/generator/negative_generator.py
@@ -47,65 +47,32 @@
         if min_length > 0:
             return "x" * (min_length - 1)
 
-    @base.generator_type("string")
+    @base.generator_type("string", needed_property="maxLength")
     @base.simple_generator
     def gen_str_max_length(self, schema):
         max_length = schema.get("maxLength", -1)
-        if max_length > -1:
-            return "x" * (max_length + 1)
+        return "x" * (max_length + 1)
 
-    @base.generator_type("integer")
+    @base.generator_type("integer", needed_property="minimum")
     @base.simple_generator
     def gen_int_min(self, schema):
-        if "minimum" in schema:
-            minimum = schema["minimum"]
-            if "exclusiveMinimum" not in schema:
-                minimum -= 1
-            return minimum
+        minimum = schema["minimum"]
+        if "exclusiveMinimum" not in schema:
+            minimum -= 1
+        return minimum
 
-    @base.generator_type("integer")
+    @base.generator_type("integer", needed_property="maximum")
     @base.simple_generator
     def gen_int_max(self, schema):
-        if "maximum" in schema:
-            maximum = schema["maximum"]
-            if "exclusiveMaximum" not in schema:
-                maximum += 1
-            return maximum
+        maximum = schema["maximum"]
+        if "exclusiveMaximum" not in schema:
+            maximum += 1
+        return maximum
 
-    @base.generator_type("object")
-    def gen_obj_remove_attr(self, schema):
-        invalids = []
-        valid_schema = valid.ValidTestGenerator().generate_valid(schema)
-        required = schema.get("required", [])
-        for r in required:
-            new_valid = copy.deepcopy(valid_schema)
-            del new_valid[r]
-            invalids.append(("gen_obj_remove_attr", new_valid, None))
-        return invalids
-
-    @base.generator_type("object")
+    @base.generator_type("object", needed_property="additionalProperties")
     @base.simple_generator
     def gen_obj_add_attr(self, schema):
         valid_schema = valid.ValidTestGenerator().generate_valid(schema)
-        if not schema.get("additionalProperties", True):
-            new_valid = copy.deepcopy(valid_schema)
-            new_valid["$$$$$$$$$$"] = "xxx"
-            return new_valid
-
-    @base.generator_type("object")
-    def gen_inv_prop_obj(self, schema):
-        LOG.debug("generate_invalid_object: %s" % schema)
-        valid_schema = valid.ValidTestGenerator().generate_valid(schema)
-        invalids = []
-        properties = schema["properties"]
-
-        for k, v in properties.iteritems():
-            for invalid in self.generate(v):
-                LOG.debug(v)
-                new_valid = copy.deepcopy(valid_schema)
-                new_valid[k] = invalid[1]
-                name = "prop_%s_%s" % (k, invalid[0])
-                invalids.append((name, new_valid, invalid[2]))
-
-        LOG.debug("generate_invalid_object return: %s" % invalids)
-        return invalids
+        new_valid = copy.deepcopy(valid_schema)
+        new_valid["$$$$$$$$$$"] = "xxx"
+        return new_valid
diff --git a/tempest/common/generator/valid_generator.py b/tempest/common/generator/valid_generator.py
index 0d7b398..7b80afc 100644
--- a/tempest/common/generator/valid_generator.py
+++ b/tempest/common/generator/valid_generator.py
@@ -54,5 +54,28 @@
             obj[k] = self.generate_valid(v)
         return obj
 
+    def generate(self, schema):
+        schema_type = schema["type"]
+        if isinstance(schema_type, list):
+            if "integer" in schema_type:
+                schema_type = "integer"
+            else:
+                raise Exception("non-integer list types not supported")
+        result = []
+        if schema_type not in self.types_dict:
+            raise TypeError("generator (%s) doesn't support type: %s"
+                            % (self.__class__.__name__, schema_type))
+        for generator in self.types_dict[schema_type]:
+            ret = generator(schema)
+            if ret is not None:
+                if isinstance(ret, list):
+                    result.extend(ret)
+                elif isinstance(ret, tuple):
+                    result.append(ret)
+                else:
+                    raise Exception("generator (%s) returns invalid result: %s"
+                                    % (generator, ret))
+        return result
+
     def generate_valid(self, schema):
         return self.generate(schema)[0][1]
diff --git a/tempest/test.py b/tempest/test.py
index 4a22b1b..5a71b7c 100644
--- a/tempest/test.py
+++ b/tempest/test.py
@@ -510,13 +510,9 @@
                                              "expected_result": expected_result
                                              }))
         if schema is not None:
-            for name, schema, expected_result in generator.generate(schema):
-                if (expected_result is None and
-                    "default_result_code" in description):
-                    expected_result = description["default_result_code"]
-                scenario_list.append((name,
-                                      {"schema": schema,
-                                       "expected_result": expected_result}))
+            for scenario in generator.generate_scenarios(schema):
+                scenario_list.append((scenario['_negtest_name'],
+                                      scenario))
         LOG.debug(scenario_list)
         return scenario_list
 
@@ -546,8 +542,14 @@
         """
         LOG.info("Executing %s" % description["name"])
         LOG.debug(description)
+        generator = importutils.import_class(
+            CONF.negative.test_generator)()
+        schema = description.get("json-schema", None)
         method = description["http-method"]
         url = description["url"]
+        expected_result = None
+        if "default_result_code" in description:
+            expected_result = description["default_result_code"]
 
         resources = [self.get_resource(r) for
                      r in description.get("resources", [])]
@@ -557,13 +559,19 @@
             # entry (see get_resource).
             # We just send a valid json-schema with it
             valid_schema = None
-            schema = description.get("json-schema", None)
             if schema:
                 valid_schema = \
                     valid.ValidTestGenerator().generate_valid(schema)
             new_url, body = self._http_arguments(valid_schema, url, method)
-        elif hasattr(self, "schema"):
-            new_url, body = self._http_arguments(self.schema, url, method)
+        elif hasattr(self, "_negtest_name"):
+            schema_under_test = \
+                valid.ValidTestGenerator().generate_valid(schema)
+            local_expected_result = \
+                generator.generate_payload(self, schema_under_test)
+            if local_expected_result is not None:
+                expected_result = local_expected_result
+            new_url, body = \
+                self._http_arguments(schema_under_test, url, method)
         else:
             raise Exception("testscenarios are not active. Please make sure "
                             "that your test runner supports the load_tests "
@@ -575,7 +583,7 @@
             client = self.client
         resp, resp_body = client.send_request(method, new_url,
                                               resources, body=body)
-        self._check_negative_response(resp.status, resp_body)
+        self._check_negative_response(expected_result, resp.status, resp_body)
 
     def _http_arguments(self, json_dict, url, method):
         LOG.debug("dict: %s url: %s method: %s" % (json_dict, url, method))
@@ -586,8 +594,7 @@
         else:
             return url, json.dumps(json_dict)
 
-    def _check_negative_response(self, result, body):
-        expected_result = getattr(self, "expected_result", None)
+    def _check_negative_response(self, expected_result, result, body):
         self.assertTrue(result >= 400 and result < 500 and result != 413,
                         "Expected client error, got %s:%s" %
                         (result, body))
diff --git a/tempest/tests/negative/test_negative_auto_test.py b/tempest/tests/negative/test_negative_auto_test.py
index dddd083..fb1da43 100644
--- a/tempest/tests/negative/test_negative_auto_test.py
+++ b/tempest/tests/negative/test_negative_auto_test.py
@@ -43,9 +43,9 @@
     def _check_prop_entries(self, result, entry):
         entries = [a for a in result if entry in a[0]]
         self.assertIsNotNone(entries)
-        self.assertIs(len(entries), 2)
+        self.assertGreater(len(entries), 1)
         for entry in entries:
-            self.assertIsNotNone(entry[1]['schema'])
+            self.assertIsNotNone(entry[1]['_negtest_name'])
 
     def _check_resource_entries(self, result, entry):
         entries = [a for a in result if entry in a[0]]
@@ -57,12 +57,11 @@
     def test_generate_scenario(self):
         scenarios = test.NegativeAutoTest.\
             generate_scenario(self.fake_input_desc)
-
         self.assertIsInstance(scenarios, list)
         for scenario in scenarios:
             self.assertIsInstance(scenario, tuple)
             self.assertIsInstance(scenario[0], str)
             self.assertIsInstance(scenario[1], dict)
-        self._check_prop_entries(scenarios, "prop_minRam")
-        self._check_prop_entries(scenarios, "prop_minDisk")
+        self._check_prop_entries(scenarios, "minRam")
+        self._check_prop_entries(scenarios, "minDisk")
         self._check_resource_entries(scenarios, "inv_res")
diff --git a/tempest/tests/negative/test_negative_generators.py b/tempest/tests/negative/test_negative_generators.py
index a7af619..2fa6933 100644
--- a/tempest/tests/negative/test_negative_generators.py
+++ b/tempest/tests/negative/test_negative_generators.py
@@ -13,6 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import copy
+
 import jsonschema
 import mock
 
@@ -86,15 +88,6 @@
 class BaseNegativeGenerator(object):
     types = ['string', 'integer', 'object']
 
-    fake_input_str = {"type": "string",
-                      "minLength": 2,
-                      "maxLength": 8,
-                      'results': {'gen_int': 404}}
-
-    fake_input_int = {"type": "integer",
-                      "maximum": 255,
-                      "minimum": 1}
-
     fake_input_obj = {"type": "object",
                       "properties": {"minRam": {"type": "integer"},
                                      "diskName": {"type": "string"},
@@ -106,31 +99,21 @@
         "type": "not_defined"
     }
 
-    def _validate_result(self, data):
-        self.assertTrue(isinstance(data, list))
-        for t in data:
-            self.assertIsInstance(t, tuple)
-            self.assertEqual(3, len(t))
-            self.assertIsInstance(t[0], str)
+    class fake_test_class(object):
+        def __init__(self, scenario):
+            for k, v in scenario.iteritems():
+                setattr(self, k, v)
 
-    def test_generate_string(self):
-        result = self.generator.generate(self.fake_input_str)
-        self._validate_result(result)
-
-    def test_generate_integer(self):
-        result = self.generator.generate(self.fake_input_int)
-        self._validate_result(result)
-
-    def test_generate_obj(self):
-        result = self.generator.generate(self.fake_input_obj)
-        self._validate_result(result)
+    def _validate_result(self, valid_schema, invalid_schema):
+        for k, v in valid_schema.iteritems():
+            self.assertTrue(k in invalid_schema)
 
     def test_generator_mandatory_functions(self):
         for data_type in self.types:
             self.assertIn(data_type, self.generator.types_dict)
 
     def test_generate_with_unknown_type(self):
-        self.assertRaises(TypeError, self.generator.generate,
+        self.assertRaises(TypeError, self.generator.generate_payload,
                           self.unknown_type_schema)
 
 
@@ -151,3 +134,16 @@
     def setUp(self):
         super(TestNegativeNegativeGenerator, self).setUp()
         self.generator = negative_generator.NegativeTestGenerator()
+
+    def test_generate_obj(self):
+        schema = self.fake_input_obj
+        scenarios = self.generator.generate_scenarios(schema)
+        for scenario in scenarios:
+            test = self.fake_test_class(scenario)
+            valid_schema = \
+                valid_generator.ValidTestGenerator().generate_valid(schema)
+            schema_under_test = copy.copy(valid_schema)
+            expected_result = \
+                self.generator.generate_payload(test, schema_under_test)
+            self.assertEqual(expected_result, None)
+            self._validate_result(valid_schema, schema_under_test)