diff --git a/module_build_service/builder/KojiModuleBuilder.py b/module_build_service/builder/KojiModuleBuilder.py
index 7fbcd3d1..a61a2995 100644
--- a/module_build_service/builder/KojiModuleBuilder.py
+++ b/module_build_service/builder/KojiModuleBuilder.py
@@ -40,16 +40,105 @@ import threading
 import munch
 from OpenSSL.SSL import SysCallError
 
-from module_build_service import log
+from module_build_service import log, conf
 import module_build_service.scm
 import module_build_service.utils
 from module_build_service.builder.utils import execute_cmd
+from module_build_service.errors import ProgrammingError
 
 from base import GenericBuilder
 
 logging.basicConfig(level=logging.DEBUG)
 
 
+def koji_multicall_map(koji_session, koji_session_fnc, list_of_args=None, list_of_kwargs=None):
+    """
+    Calls the `koji_session_fnc` using Koji multicall feature N times based on the list of
+    arguments passed in `list_of_args` and `list_of_kwargs`.
+    Returns list of responses sorted the same way as input args/kwargs. In case of error,
+    the error message is logged and None is returned.
+
+    For example to get the package ids of "httpd" and "apr" packages:
+        ids = koji_multicall_map(session, session.getPackageID, ["httpd", "apr"])
+        # ids is now [280, 632]
+
+    :param KojiSessions koji_session: KojiSession to use for multicall.
+    :param object koji_session_fnc: Python object representing the KojiSession method to call.
+    :param list list_of_args: List of args which are passed to each call of koji_session_fnc.
+    :param list list_of_kwargs: List of kwargs which are passed to each call of koji_session_fnc.
+    """
+    if list_of_args is None and list_of_kwargs is None:
+        raise ProgrammingError("One of list_of_args or list_of_kwargs must be set.")
+
+    if (type(list_of_args) not in [type(None), list] or
+            type(list_of_kwargs) not in [type(None), list]):
+        raise ProgrammingError("list_of_args and list_of_kwargs must be list or None.")
+
+    if list_of_kwargs is None:
+        list_of_kwargs = [{}] * len(list_of_args)
+    if list_of_args is None:
+        list_of_args = [[]] * len(list_of_kwargs)
+
+    if len(list_of_args) != len(list_of_kwargs):
+        raise ProgrammingError("Length of list_of_args and list_of_kwargs must be the same.")
+
+    koji_session.multicall = True
+    for args, kwargs in zip(list_of_args, list_of_kwargs):
+        if type(args) != list:
+            args = [args]
+        if type(kwargs) != dict:
+            raise ProgrammingError("Every item in list_of_kwargs must be a dict")
+        koji_session_fnc(*args, **kwargs)
+
+    try:
+        responses = koji_session.multiCall(strict=True)
+    except Exception:
+        log.exception("Exception raised for multicall of method %r with args %r, %r:",
+                      koji_session_fnc, args, kwargs)
+        return None
+
+    if not responses:
+        log.error("Koji did not return response for multicall of %r", koji_session_fnc)
+        return None
+    if type(responses) != list:
+        log.error("Fault element was returned for multicall of method %r: %r",
+                  koji_session_fnc, responses)
+        return None
+
+    results = []
+
+    # For the response specification, see
+    # https://web.archive.org/web/20060624230303/http://www.xmlrpc.com/discuss/msgReader$1208?mode=topic
+    # Relevant part of this:
+    # Multicall returns an array of responses. There will be one response for each call in
+    # the original array. The result will either be a one-item array containing the result value,
+    # or a struct of the form found inside the standard <fault> element.
+    for response, args, kwargs in zip(responses, list_of_args, list_of_kwargs):
+        if type(response) == list:
+            if not response:
+                log.error("Empty list returned for multicall of method %r with args %r, %r",
+                          koji_session_fnc, args, kwargs)
+                return None
+            results.append(response[0])
+        else:
+            log.error("Unexpected data returned for multicall of method %r with args %r, %r: %r",
+                      koji_session_fnc, args, kwargs, response)
+            return None
+
+    return results
+
+
+@module_build_service.utils.retry(wait_on=(xmlrpclib.ProtocolError, koji.GenericError))
+def koji_retrying_multicall_map(*args, **kwargs):
+    """
+    Retrying version of koji_multicall_map. This tries to retry the Koji call
+    in case of koji.GenericError or xmlrpclib.ProtocolError.
+
+    Please refer to koji_multicall_map for further specification of arguments.
+    """
+    return koji_multicall_map(*args, **kwargs)
+
+
 class KojiModuleBuilder(GenericBuilder):
     """ Koji specific builder class """
 
@@ -809,7 +898,8 @@ chmod 644 %buildroot/%_sysconfdir/rpm/macros.zz-modules
 
         return tasks
 
-    def get_average_build_time(self, component):
+    @classmethod
+    def get_average_build_time(cls, component):
         """
         Get the average build time of the component from Koji
         :param component: a ComponentBuild object
@@ -817,4 +907,99 @@ chmod 644 %buildroot/%_sysconfdir/rpm/macros.zz-modules
         """
         # If the component has not been built before, then None is returned. Instead, let's
         # return 0.0 so the type is consistent
-        return self.koji_session.getAverageBuildDuration(component.package) or 0.0
+        koji_session = KojiModuleBuilder.get_session(conf, None)
+        return koji_session.getAverageBuildDuration(component) or 0.0
+
+    @classmethod
+    def get_build_weights(cls, components):
+        """
+        Returns a dict with component name as a key and float number
+        representing the overall Koji weight of a component build.
+        The weight is sum of weights of all tasks in a previously done modular
+        build of a component.
+
+        :param list components: List of component names.
+        :rtype: dict
+        :return: {component_name: weight_as_float, ...}
+        """
+
+        koji_session = KojiModuleBuilder.get_session(conf, None)
+
+        # Get our own userID, so we can limit the builds to only modular builds
+        user_info = koji_session.getLoggedInUser()
+        if not user_info or "id" not in user_info:
+            log.warn("Koji.getLoggedInUser() failed while getting build weight.")
+            return cls.compute_weights_from_build_time(components)
+        mbs_user_id = user_info["id"]
+
+        # Get the Koji PackageID for every component in single Koji call.
+        # If some package does not exist in Koji, component_ids will be None.
+        component_ids = koji_retrying_multicall_map(
+            koji_session, koji_session.getPackageID, list_of_args=components)
+        if not component_ids:
+            return cls.compute_weights_from_build_time(components)
+
+        # Prepare list of queries to call koji_session.listBuilds
+        build_queries = []
+        for component_id in component_ids:
+            build_queries.append({
+                "packageID": component_id,
+                "userID": mbs_user_id,
+                "state": koji.BUILD_STATES["COMPLETE"],
+                "queryOpts": {"order": "-build_id", "limit": 1}})
+
+        # Get the latest Koji build created by MBS for every component in single Koji call.
+        builds_per_component = koji_retrying_multicall_map(
+            koji_session, koji_session.listBuilds, list_of_kwargs=build_queries)
+        if not builds_per_component:
+            return cls.compute_weights_from_build_time(components)
+
+        # Get list of task_ids associated with the latest build in builds.
+        # For some packages, there may not be a build done by MBS yet.
+        # We store such packages in `components_without_build` and later
+        # compute the weight by compute_weights_from_build_time().
+        # For others, we will continue by examining weights of all tasks
+        # belonging to that build later.
+        task_ids = []
+        components_with_build = []
+        components_without_build = []
+        for builds, component_name in zip(builds_per_component, components):
+            if not builds:
+                # No build for this component.
+                components_without_build.append(component_name)
+                continue
+
+            latest_build = builds[0]
+            task_id = latest_build["task_id"]
+
+            if not task_id:
+                # No task_id for this component, this can happen for imported
+                # component builds.
+                components_without_build.append(component_name)
+                continue
+
+            components_with_build.append(component_name)
+            task_ids.append(task_id)
+
+        weights = {}
+
+        # For components without any build, fallback to weights computation based on
+        # the average time to build.
+        weights.update(cls.compute_weights_from_build_time(components_without_build))
+
+        # For components with a build, get the list of tasks associated with this build
+        # and compute the weight for each component build as sum of weights of all tasks.
+        tasks_per_latest_build = koji_retrying_multicall_map(
+            koji_session, koji_session.getTaskDescendents, list_of_args=task_ids)
+        if not tasks_per_latest_build:
+            return cls.compute_weights_from_build_time(components_with_build)
+
+        for tasks, component_name in zip(tasks_per_latest_build, components_with_build):
+            # Compute overall weight of this build. This is sum of weights
+            # of all tasks in a build.
+            weight = 0
+            for task in tasks.values():
+                weight += sum([t["weight"] for t in task])
+            weights[component_name] = weight
+
+        return weights
diff --git a/module_build_service/builder/base.py b/module_build_service/builder/base.py
index 053e0ce5..f58c948b 100644
--- a/module_build_service/builder/base.py
+++ b/module_build_service/builder/base.py
@@ -356,3 +356,72 @@ class GenericBuilder(six.with_metaclass(ABCMeta)):
         :return: a float of 0.0
         """
         return 0.0
+
+    @classmethod
+    def get_build_weights(cls, components):
+        """
+        Returns a dict with component name as a key and float number
+        representing the overall Koji weight of a component build.
+
+        :param list components: List of component names.
+        :rtype: dict
+        :return: {component_name: weight_as_float, ...}
+        """
+        return cls.compute_weights_from_build_time(components)
+
+    @classmethod
+    def compute_weights_from_build_time(cls, components, arches=None):
+        """
+        Computes the weights of ComponentBuilds based on average time to build
+        and list of arches for which the component is going to be built.
+
+        This method should be used as a fallback only when KojiModuleBuilder
+        cannot be used, because the weight this method produces is not 100% accurate.
+
+        :param components: List of comopnent names to compute the weight for.
+        :param arches: List of arches to build for or None. If the value is None,
+            conf.koji_arches will be used instead.
+        :rtype: dict
+        :return: {component_name: weight_as_float, ...}
+        """
+        if not arches:
+            arches = conf.koji_arches
+
+        weights = {}
+
+        for component in components:
+            average_time_to_build = cls.get_average_build_time(component)
+
+            # The way how `weight` is computed is based on hardcoded weight values
+            # in kojid.py.
+            # The weight computed here is not 100% accurate, because there are
+            # multiple smaller tasks in koji like waitrepo or createrepo and we
+            # cannot say if they will be executed as part of this component build.
+            # The weight computed here is used only to limit the number of builds
+            # and we generally do not care about waitrepo/createrepo weights in MBS.
+
+            # 1.5 is what Koji hardcodes as a default weight for BuildArchTask.
+            weight = 1.5
+            if not average_time_to_build:
+                weights[component] = weight
+                continue
+
+            if average_time_to_build < 0:
+                log.warn("Negative average build duration for component %s: %s",
+                         component, str(average_time_to_build))
+                weights[component] = weight
+                continue
+
+            # Increase the task weight by 0.75 for every hour of build duration.
+            adj = (average_time_to_build / ((60 * 60) / 0.75))
+            # cap the adjustment at +4.5
+            weight += min(4.5, adj)
+
+            # We build for all arches, so multiply the weight by number of arches.
+            weight = weight * len(arches)
+
+            # 1.5 here is hardcoded Koji weight of single BuildSRPMFromSCMTask
+            weight += 1.5
+            weights[component] = weight
+
+        return weights
diff --git a/module_build_service/migrations/versions/f5b1c5203cce_.py b/module_build_service/migrations/versions/f5b1c5203cce_.py
new file mode 100644
index 00000000..e086a30a
--- /dev/null
+++ b/module_build_service/migrations/versions/f5b1c5203cce_.py
@@ -0,0 +1,22 @@
+"""Add component_builds.weight
+
+Revision ID: f5b1c5203cce
+Revises: 524c3b1c683c
+Create Date: 2017-11-08 17:18:27.401546
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = 'f5b1c5203cce'
+down_revision = '524c3b1c683c'
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    op.add_column('component_builds', sa.Column('weight', sa.Float(), nullable=True))
+
+
+def downgrade():
+    op.drop_column('component_builds', 'weight')
diff --git a/module_build_service/models.py b/module_build_service/models.py
index c6438587..e8a2d81e 100644
--- a/module_build_service/models.py
+++ b/module_build_service/models.py
@@ -527,6 +527,10 @@ class ComponentBuild(MBSBase):
     reused_component_id = db.Column(
         db.Integer, db.ForeignKey('component_builds.id'))
 
+    # Weight defines the complexity of the component build as calculated by the builder's
+    # get_build_weights function
+    weight = db.Column(db.Float, default=0)
+
     @classmethod
     def from_component_event(cls, session, event):
         if isinstance(event, module_build_service.messaging.KojiBuildChange):
diff --git a/module_build_service/utils.py b/module_build_service/utils.py
index 6a68c7d4..d0cdc43e 100644
--- a/module_build_service/utils.py
+++ b/module_build_service/utils.py
@@ -165,9 +165,7 @@ def continue_batch_build(config, module, session, builder, components=None):
     components_to_build = []
     # Sort the unbuilt_components so that the components that take the longest to build are
     # first
-    log.info('Sorting the unbuilt components by their average build time')
-    unbuilt_components.sort(key=lambda c: builder.get_average_build_time(c), reverse=True)
-    log.info('Done sorting the unbuilt components by their average build time')
+    unbuilt_components.sort(key=lambda c: c.weight, reverse=True)
 
     # Check for builds that exist in the build system but MBS doesn't know about
     for component in unbuilt_components:
@@ -860,6 +858,9 @@ def merge_included_mmd(mmd, included_mmd):
 
 def record_component_builds(mmd, module, initial_batch=1,
                             previous_buildorder=None, main_mmd=None, session=None):
+    # Imported here to allow import of utils in GenericBuilder.
+    import module_build_service.builder
+
     if not session:
         session = db.session
 
@@ -890,6 +891,9 @@ def record_component_builds(mmd, module, initial_batch=1,
         components = mmd.components.all
         components.sort(key=lambda x: x.buildorder)
 
+        weights = module_build_service.builder.GenericBuilder.get_build_weights(
+            [c.name for c in components])
+
         # We do not start with batch = 0 here, because the first batch is
         # reserved for module-build-macros. First real components must be
         # planned for batch 2 and following.
@@ -922,7 +926,8 @@ def record_component_builds(mmd, module, initial_batch=1,
                 format="rpms",
                 scmurl=full_url,
                 batch=batch,
-                ref=pkgref
+                ref=pkgref,
+                weight=weights[pkg.name]
             )
             session.add(build)
 
diff --git a/tests/test_builder/test_base.py b/tests/test_builder/test_base.py
index 3371c1eb..5aa01807 100644
--- a/tests/test_builder/test_base.py
+++ b/tests/test_builder/test_base.py
@@ -68,3 +68,7 @@ class TestGenericBuilder(unittest.TestCase):
         ret = GenericBuilder.default_buildroot_groups(db.session, self.module)
         self.assertEqual(ret, expected_groups)
         resolve_profiles.assert_called_once()
+
+    def test_get_build_weights(self):
+        weights = GenericBuilder.get_build_weights(["httpd", "apr"])
+        self.assertEqual(weights, {"httpd": 1.5, "apr": 1.5})
diff --git a/tests/test_builder/test_koji.py b/tests/test_builder/test_koji.py
index 35aad747..cf2dbe9d 100644
--- a/tests/test_builder/test_koji.py
+++ b/tests/test_builder/test_koji.py
@@ -243,6 +243,101 @@ class TestKojiBuilder(unittest.TestCase):
         builder.koji_session.tagBuild.assert_called_once_with(
             builder.module_tag["id"], "new-1.0-1.module_e0095747")
 
+    @patch('module_build_service.builder.KojiModuleBuilder.KojiModuleBuilder.get_session')
+    def test_get_build_weights(self, get_session):
+        session = MagicMock()
+        session.getLoggedInUser.return_value = {"id": 123}
+        session.multiCall.side_effect = [
+            # getPackageID response
+            [[1], [2]],
+            # listBuilds response
+            [[[{"task_id": 456}]], [[{"task_id": 789}]]],
+            # getTaskDescendents response
+            [[{'1': [], '2': [], '3': [{'weight': 1.0}, {'weight': 1.0}]}],
+             [{'1': [], '2': [], '3': [{'weight': 1.0}, {'weight': 1.0}]}]]
+        ]
+        get_session.return_value = session
+
+        weights = KojiModuleBuilder.get_build_weights(["httpd", "apr"])
+        self.assertEqual(weights, {"httpd": 2, "apr": 2})
+
+        expected_calls = [mock.call(456), mock.call(789)]
+        self.assertEqual(session.getTaskDescendents.mock_calls, expected_calls)
+
+    @patch('module_build_service.builder.KojiModuleBuilder.KojiModuleBuilder.get_session')
+    def test_get_build_weights_no_task_id(self, get_session):
+        session = MagicMock()
+        session.getLoggedInUser.return_value = {"id": 123}
+        session.multiCall.side_effect = [
+            # getPackageID response
+            [[1], [2]],
+            # listBuilds response
+            [[[{"task_id": 456}]], [[{"task_id": None}]]],
+            # getTaskDescendents response
+            [[{'1': [], '2': [], '3': [{'weight': 1.0}, {'weight': 1.0}]}]]
+        ]
+        get_session.return_value = session
+
+        weights = KojiModuleBuilder.get_build_weights(["httpd", "apr"])
+        self.assertEqual(weights, {"httpd": 2, "apr": 1.5})
+
+        expected_calls = [mock.call(456)]
+        self.assertEqual(session.getTaskDescendents.mock_calls, expected_calls)
+
+    @patch('module_build_service.builder.KojiModuleBuilder.KojiModuleBuilder.get_session')
+    def test_get_build_weights_no_build(self, get_session):
+        session = MagicMock()
+        session.getLoggedInUser.return_value = {"id": 123}
+        session.multiCall.side_effect = [
+            # getPackageID response
+            [[1], [2]],
+            # listBuilds response
+            [[[{"task_id": 456}]], [[]]],
+            # getTaskDescendents response
+            [[{'1': [], '2': [], '3': [{'weight': 1.0}, {'weight': 1.0}]}]]
+        ]
+        get_session.return_value = session
+
+        weights = KojiModuleBuilder.get_build_weights(["httpd", "apr"])
+        self.assertEqual(weights, {"httpd": 2, "apr": 1.5})
+
+        expected_calls = [mock.call(456)]
+        self.assertEqual(session.getTaskDescendents.mock_calls, expected_calls)
+
+    @patch('module_build_service.builder.KojiModuleBuilder.KojiModuleBuilder.get_session')
+    def test_get_build_weights_listBuilds_failed(self, get_session):
+        session = MagicMock()
+        session.getLoggedInUser.return_value = {"id": 123}
+        session.multiCall.side_effect = [[[1], [2]], []]
+        get_session.return_value = session
+
+        weights = KojiModuleBuilder.get_build_weights(["httpd", "apr"])
+        self.assertEqual(weights, {"httpd": 1.5, "apr": 1.5})
+
+        expected_calls = [mock.call(packageID=1, userID=123, state=1,
+                                    queryOpts={'limit': 1, 'order': '-build_id'}),
+                          mock.call(packageID=2, userID=123, state=1,
+                                    queryOpts={'limit': 1, 'order': '-build_id'})]
+        self.assertEqual(session.listBuilds.mock_calls, expected_calls)
+
+    @patch('module_build_service.builder.KojiModuleBuilder.KojiModuleBuilder.get_session')
+    def test_get_build_weights_getPackageID_failed(self, get_session):
+        session = MagicMock()
+        session.getLoggedInUser.return_value = {"id": 123}
+        session.multiCall.side_effect = [[], []]
+        get_session.return_value = session
+
+        weights = KojiModuleBuilder.get_build_weights(["httpd", "apr"])
+        self.assertEqual(weights, {"httpd": 1.5, "apr": 1.5})
+
+        expected_calls = [mock.call("httpd"), mock.call("apr")]
+        self.assertEqual(session.getPackageID.mock_calls, expected_calls)
+
+    @patch('module_build_service.builder.KojiModuleBuilder.KojiModuleBuilder.get_session')
+    def test_get_build_weights_getLoggedInUser_failed(self, get_session):
+        weights = KojiModuleBuilder.get_build_weights(["httpd", "apr"])
+        self.assertEqual(weights, {"httpd": 1.5, "apr": 1.5})
+
 
 class TestGetKojiClientSession(unittest.TestCase):
 
diff --git a/tests/test_utils/test_utils.py b/tests/test_utils/test_utils.py
index 483804cf..084d17ef 100644
--- a/tests/test_utils/test_utils.py
+++ b/tests/test_utils/test_utils.py
@@ -32,7 +32,8 @@ import module_build_service.scm
 from module_build_service import models, conf
 from module_build_service.errors import ProgrammingError, ValidationError, UnprocessableEntity
 from tests import (test_reuse_component_init_data, init_data, db,
-                   test_reuse_shared_userspace_init_data)
+                   test_reuse_shared_userspace_init_data,
+                   clean_database)
 import mock
 import koji
 import module_build_service.scheduler.handlers.components
@@ -704,6 +705,43 @@ class TestUtils(unittest.TestCase):
             assert username_arg == username
         rmtree(module_dir)
 
+    @vcr.use_cassette(
+        path.join(CASSETTES_DIR, ('tests.test_utils.TestUtils.'
+                                  'test_record_component_builds_set_weight')))
+    @patch('module_build_service.scm.SCM')
+    def test_record_component_builds_set_weight(self, mocked_scm):
+        with app.app_context():
+            clean_database()
+            mocked_scm.return_value.commit = \
+                '620ec77321b2ea7b0d67d82992dda3e1d67055b4'
+            # For all the RPMs in testmodule, get_latest is called
+            hashes_returned = {
+                'f25': '4ceea43add2366d8b8c5a622a2fb563b625b9abf',
+                'f24': 'fbed359411a1baa08d4a88e0d12d426fbf8f602c'}
+
+            def mocked_get_latest(branch="master"):
+                return hashes_returned[branch]
+
+            mocked_scm.return_value.get_latest = mocked_get_latest
+
+            testmodule_variant_mmd_path = path.join(
+                BASE_DIR, '..', 'staged_data', 'testmodule-variant.yaml')
+            testmodule_variant_mmd = modulemd.ModuleMetadata()
+            with open(testmodule_variant_mmd_path) as mmd_file:
+                testmodule_variant_mmd.loads(mmd_file)
+
+            mmd = testmodule_variant_mmd
+            module_build = models.ModuleBuild.create(
+                db.session, conf, "test", "stream", "1", mmd.dumps(), "scmurl", "owner")
+
+            module_build_service.utils.record_component_builds(
+                mmd, module_build)
+
+            self.assertEqual(module_build.state, models.BUILD_STATES['init'])
+            db.session.refresh(module_build)
+            for c in module_build.component_builds:
+                self.assertEqual(c.weight, 1.5)
+
 
 class DummyModuleBuilder(GenericBuilder):
     """
@@ -971,12 +1009,13 @@ class TestBatches(unittest.TestCase):
             module_id=2, package='perl-List-Compare').one()
         plc_component.ref = '5ceea46add2366d8b8c5a623a2fb563b625b9abd'
 
+        # Components are by default built by component id. To find out that weight is respected,
+        # we have to set bigger weight to component with lower id.
+        pt_component.weight = 3 if pt_component.id < plc_component.id else 4
+        plc_component.weight = 4 if pt_component.id < plc_component.id else 3
+
         builder = mock.MagicMock()
         builder.recover_orphaned_artifact.return_value = []
-        # The call order of get_average_build_time should be by the component's ID. Having this
-        # side_effect tells continue_batch_build to build the second component in the build batch
-        # first and the first component in the build batch second.
-        builder.get_average_build_time.side_effect = [1234.56, 2345.67]
         further_work = module_build_service.utils.start_next_batch_build(
             conf, module_build, db.session, builder)
 
diff --git a/tests/vcr-request-data.tar.gz b/tests/vcr-request-data.tar.gz
index 94ef0f79..35a5dd9d 100644
Binary files a/tests/vcr-request-data.tar.gz and b/tests/vcr-request-data.tar.gz differ