diff --git a/.travis.yml b/.travis.yml
index 466e7046e41c4600709b215c72fb580c26c57b05..792ae8f17fe19012b96690c2e1f9fa25abbd51d3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -29,7 +29,7 @@ dist: xenial
 
 install:
   - cd "$TRAVIS_BUILD_DIR"
-  - sudo ./install_base_ubuntu.sh
+  - sudo ./install_base_ubuntu.sh --install-doc-extras
   - echo "$(python3 --version)"
 
 script:
diff --git a/doc/conf.py b/doc/conf.py
index ba697c06863adeed09d12b0d0f2e13950467b209..2af97de94e64be15fdc559fe7f61bb858b04a4cf 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -98,6 +98,8 @@ extensions = [
     'sphinx.ext.coverage',
     'sphinx.ext.imgmath',
     'sphinx.ext.viewcode',
+    'sphinx.ext.inheritance_diagram',
+    'sphinxcontrib.plantuml',
 ]
 
 # Add any paths that contain templates here, relative to this directory.
diff --git a/doc/kernel_tests.rst b/doc/kernel_tests.rst
index 8f8e636bc9d009610f7cc81ea2cc1794dad8ddec..c7ed538c12ec9975a666b46bd40892f0c4c91a28 100644
--- a/doc/kernel_tests.rst
+++ b/doc/kernel_tests.rst
@@ -69,8 +69,8 @@ See the usage example of :class:`~lisa.tests.base.TestBundle`
 Writing tests
 =============
 
-Basics
-++++++
+Concepts
+++++++++
 
 Writing scheduler tests can be difficult, especially when you're
 trying to make them work without relying on custom tracepoints (which is
@@ -94,7 +94,70 @@ Have a look at its documentation for implementation and usage examples.
    A simple test implementation worth looking at is
    :class:`~lisa.tests.scheduler.sanity.CapacitySanity`.
 
-Implementations of :class:`~lisa.tests.base.TestBundle` can
+The relationship between the test classes has been condensed into this diagram,
+although you'll find more details in the API documentation of these classes.
+
+.. uml::
+
+  class TestMetric {
+	+ data
+	+ units
+  }
+
+
+  note bottom of TestMetric {
+       TestMetrics serve to answer
+       <b>"Why did my test fail/pass ?"</b>.
+       They are free-form, so they can be
+       error counts, durations, stats...
+  }
+
+  class Result {
+	PASSED
+	FAILED
+	UNDECIDED
+  }
+
+  class ResultBundle {
+	+ result : Result
+	+ add_metric()
+  }
+
+  ResultBundle "1" *- "1" Result
+  ' This forces a longer arrow ------------v
+  ResultBundle "1" *- "1..*" TestMetric : "          "
+
+  class TestBundle {
+      # _from_target() : TestBundle
+      + from_target() : TestBundle
+      + from_dir() : TestBundle
+  }
+
+  note right of TestBundle {
+      Methods returning <b>TestBundle</b>
+      are alternative constructors
+
+      <b>from_target()</b> does some generic
+      work, then calls <b>_from_target()</b>. You'll
+      have to override it depending on what
+      you want to execute on the target.
+  }
+
+  class MyTestBundle {
+	# _from_target() : TestBundle
+	+ test_foo_is_bar() : ResultBundle
+  }
+
+  note right of MyTestBundle {
+      Non-abstract <b>TestBundle</b> classes
+      must define test methods that return
+      a <b>ResultBundle</b>
+  }
+
+  TestBundle <|-- MyTestBundle
+  MyTestBundle .. ResultBundle
+
+Implementations of :class:`~lisa.tests.base.TestBundle._from_target` can
 execute any sort of arbitry Python code. This means that you are free to
 manipulate sysfs entries, or to execute arbitray binaries on the target. The
 :class:`~lisa.wlgen.workload.Workload` class has been created to
@@ -109,8 +172,8 @@ tasks with a pre-determined utilization.
 API
 ===
 
-Base API
-++++++++
+Base classes
+++++++++++++
 
 .. automodule:: lisa.tests.base
    :members:
@@ -123,11 +186,25 @@ Scheduler tests
 
 EAS tests
 ---------
+
+.. inheritance-diagram:: lisa.tests.scheduler.eas_behaviour
+   :top-classes: lisa.tests.base.TestBundle
+   :parts: 1
+
+|
+
 .. automodule:: lisa.tests.scheduler.eas_behaviour
    :members:
 
 Load tracking tests
 -------------------
+
+.. inheritance-diagram:: lisa.tests.scheduler.load_tracking
+   :top-classes: lisa.tests.base.TestBundle
+   :parts: 1
+
+|
+
 .. automodule:: lisa.tests.scheduler.load_tracking
    :members:
    :private-members: _from_target
@@ -135,23 +212,48 @@ Load tracking tests
 Misfit tests
 ------------
 
+.. inheritance-diagram:: lisa.tests.scheduler.misfit
+   :top-classes: lisa.tests.base.TestBundle
+   :parts: 1
+
+|
+
 .. automodule:: lisa.tests.scheduler.misfit
    :members:
 
 Sanity tests
 ------------
 
+.. inheritance-diagram:: lisa.tests.scheduler.sanity
+   :top-classes: lisa.tests.base.TestBundle
+   :parts: 1
+
+|
+
 .. automodule:: lisa.tests.scheduler.sanity
    :members:
 
 Hotplug tests
 +++++++++++++
+
+.. inheritance-diagram:: lisa.tests.hotplug.torture
+   :top-classes: lisa.tests.base.TestBundle
+   :parts: 1
+
+|
+
 .. automodule:: lisa.tests.hotplug.torture
    :members:
 
 Cpufreq tests
 +++++++++++++
 
+.. inheritance-diagram:: lisa.tests.cpufreq.sanity
+   :top-classes: lisa.tests.base.TestBundle
+   :parts: 1
+
+|
+
 .. automodule:: lisa.tests.cpufreq.sanity
    :members:
 
diff --git a/install_base_ubuntu.sh b/install_base_ubuntu.sh
index 637789bd322dd8ff6a39bf9a224d1a6a3dbbe183..6fcdda47a3355102a9def8fc41891845ceb0cc44 100755
--- a/install_base_ubuntu.sh
+++ b/install_base_ubuntu.sh
@@ -10,7 +10,7 @@ SCRIPT_DIR=$(dirname "${BASH_SOURCE[0]}")
 cd "$SCRIPT_DIR"
 
 usage() {
-    echo Usage: "$0" [--install-android-sdk]
+    echo Usage: "$0" [--install-android-sdk] [--install-doc-extras]
 }
 
 latest_version() {
@@ -59,13 +59,20 @@ install_nodejs() {
     apt-get install -y nodejs npm
 }
 
+install_doc_extras() {
+    apt-get -y install plantuml graphviz
+}
+
 set -eu
 
 install_android_sdk=n
+install_doc_extras=n
 
 for arg in "$@"; do
     if [ "$arg" == "--install-android-sdk" ]; then
-        install_android_sdk=y
+	install_android_sdk=y
+    elif [ "$arg" == "--install-doc-extras" ]; then
+	install_doc_extras=y
     else
         echo "Unrecognised argument: $arg"
         usage
@@ -87,6 +94,10 @@ if [ "$install_android_sdk" == y ]; then
     install_sdk
 fi
 
+if [ "$install_doc_extras" == y ]; then
+    install_doc_extras
+fi
+
 # Make sure we exit with no errors, so we can start making use of that
 # if we introduce some meaningful error handling. Since some packages are not
 # needed for some tasks and since we don't have mechanisms in place to group
diff --git a/lisa/tests/base.py b/lisa/tests/base.py
index f16a219d616067a6cf6c9ad689fcfdc5494f9af1..5d8e10033e303dd5efc70f466bca1c10a449866f 100644
--- a/lisa/tests/base.py
+++ b/lisa/tests/base.py
@@ -194,10 +194,10 @@ class TestBundle(Serializable, abc.ABC):
         a :class:`TestBundle`.
       * :attr:`VERIFY_SERIALIZATION` is there to ensure both above methods remain
         operationnal at all times.
-      * `res_dir` parameter of `__init__` must be stored as an attribute
+      * ``res_dir`` parameter of ``__init__`` must be stored as an attribute
         without further processing, in order to support result directory
         relocation.
-      * Test methodes should have a return annotation for the
+      * Test methods should have a return annotation for the
         :class:`ResultBundle` to be picked up by the test runners.
 
     **Implementation example**::
@@ -348,7 +348,7 @@ class TestBundle(Serializable, abc.ABC):
         """
         super().to_path(self._filepath(res_dir))
 
-class RTATestBundle(TestBundle, abc.ABC):
+class RTATestBundle(TestBundle):
     """
     "Abstract" class for :class:`lisa.wlgen.rta.RTA`-powered TestBundles
 
diff --git a/lisa/tests/hotplug/torture.py b/lisa/tests/hotplug/torture.py
index 74f0966322de72eb42274b7a1fb5bbaded63eeed..e8bb6e7b17d2f0546e0a8b8f2a3b498ce60b91e1 100644
--- a/lisa/tests/hotplug/torture.py
+++ b/lisa/tests/hotplug/torture.py
@@ -33,7 +33,7 @@ from lisa.utils import ArtifactPath
 class CPUHPSequenceError(Exception):
     pass
 
-class HotplugBase(TestBundle, abc.ABC):
+class HotplugBase(TestBundle):
     def __init__(self, plat_info, target_alive, hotpluggable_cpus, live_cpus):
         res_dir = None
         super().__init__(res_dir, plat_info)
diff --git a/lisa/tests/scheduler/eas_behaviour.py b/lisa/tests/scheduler/eas_behaviour.py
index 00241183caf8799ddc5f9d75a145b95459c20580..3970ddcbc6bac084d91de7a4540cdb6cae6e879c 100644
--- a/lisa/tests/scheduler/eas_behaviour.py
+++ b/lisa/tests/scheduler/eas_behaviour.py
@@ -36,7 +36,7 @@ from lisa.trace import requires_events
 from lisa.target import Target
 from lisa.trace import FtraceCollector
 
-class EASBehaviour(RTATestBundle, abc.ABC):
+class EASBehaviour(RTATestBundle):
     """
     Abstract class for EAS behavioural testing.
 
diff --git a/setup.py b/setup.py
index cb1178d3037ae6ef76dc4e1777ed5e3ec7be8e06..b9c67637d64c18202a8221f0d859697d00210de7 100755
--- a/setup.py
+++ b/setup.py
@@ -114,7 +114,8 @@ setup(
 
         "doc": [
             "sphinx >= 1.8",
-            "sphinx_rtd_theme"
+            "sphinx_rtd_theme",
+            "sphinxcontrib-plantuml",
         ],
 
         "test": [