diff --git a/tests/meson.build b/tests/meson.build
index 89c6a00..5c21d88 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -11,9 +11,10 @@
     executable(
         'telemetry-ut',
         [
-            '../src/details/collection_function.cpp',
             '../src/discrete_threshold.cpp',
             '../src/metric.cpp',
+            '../src/metrics/collection_data.cpp',
+            '../src/metrics/collection_function.cpp',
             '../src/numeric_threshold.cpp',
             '../src/on_change_threshold.cpp',
             '../src/persistent_json_storage.cpp',
@@ -36,6 +37,7 @@
             'src/test_conversion.cpp',
             'src/test_detached_timer.cpp',
             'src/test_discrete_threshold.cpp',
+            'src/test_ensure.cpp',
             'src/test_generate_id.cpp',
             'src/test_metric.cpp',
             'src/test_numeric_threshold.cpp',
diff --git a/tests/src/mocks/metric_listener_mock.hpp b/tests/src/mocks/metric_listener_mock.hpp
new file mode 100644
index 0000000..2e3daf9
--- /dev/null
+++ b/tests/src/mocks/metric_listener_mock.hpp
@@ -0,0 +1,11 @@
+#pragma once
+
+#include "interfaces/metric_listener.hpp"
+
+#include <gmock/gmock.h>
+
+class MetricListenerMock : public interfaces::MetricListener
+{
+  public:
+    MOCK_METHOD(void, metricUpdated, (), (override));
+};
diff --git a/tests/src/mocks/metric_mock.hpp b/tests/src/mocks/metric_mock.hpp
index 268b681..a223734 100644
--- a/tests/src/mocks/metric_mock.hpp
+++ b/tests/src/mocks/metric_mock.hpp
@@ -13,6 +13,9 @@
 
         ON_CALL(*this, getReadings())
             .WillByDefault(Return(std::vector<MetricValue>()));
+        ON_CALL(*this, sensorCount).WillByDefault(InvokeWithoutArgs([this] {
+            return getReadings().size();
+        }));
     }
 
     MOCK_METHOD(void, initialize, (), (override));
@@ -20,9 +23,11 @@
     MOCK_METHOD(std::vector<MetricValue>, getReadings, (), (const, override));
     MOCK_METHOD(LabeledMetricParameters, dumpConfiguration, (),
                 (const, override));
-
-    uint64_t sensorCount() const override
-    {
-        return getReadings().size();
-    }
+    MOCK_METHOD(uint64_t, sensorCount, (), (const, override));
+    MOCK_METHOD(void, registerForUpdates, (interfaces::MetricListener&),
+                (override));
+    MOCK_METHOD(void, unregisterFromUpdates, (interfaces::MetricListener&),
+                (override));
+    MOCK_METHOD(void, updateReadings, (Milliseconds), (override));
+    MOCK_METHOD(bool, isTimerRequired, (), (const, override));
 };
diff --git a/tests/src/mocks/sensor_listener_mock.hpp b/tests/src/mocks/sensor_listener_mock.hpp
index a5c0331..d23e349 100644
--- a/tests/src/mocks/sensor_listener_mock.hpp
+++ b/tests/src/mocks/sensor_listener_mock.hpp
@@ -7,21 +7,6 @@
 class SensorListenerMock : public interfaces::SensorListener
 {
   public:
-    void delegateIgnoringArgs()
-    {
-        using namespace testing;
-
-        ON_CALL(*this, sensorUpdated(_, _))
-            .WillByDefault(InvokeWithoutArgs([this] { sensorUpdated(); }));
-
-        ON_CALL(*this, sensorUpdated(_, _, _))
-            .WillByDefault(InvokeWithoutArgs([this] { sensorUpdated(); }));
-    }
-
-    MOCK_METHOD(void, sensorUpdated, (interfaces::Sensor&, Milliseconds),
-                (override));
     MOCK_METHOD(void, sensorUpdated,
                 (interfaces::Sensor&, Milliseconds, double), (override));
-
-    MOCK_METHOD(void, sensorUpdated, (), ());
 };
diff --git a/tests/src/params/metric_params.hpp b/tests/src/params/metric_params.hpp
index 90db484..cc5519d 100644
--- a/tests/src/params/metric_params.hpp
+++ b/tests/src/params/metric_params.hpp
@@ -79,6 +79,17 @@
         return expectedReadingProperty;
     }
 
+    bool expectedIsTimerRequired() const
+    {
+        return expectedIsTimerRequiredProperty;
+    }
+
+    MetricParams& expectedIsTimerRequired(bool value)
+    {
+        expectedIsTimerRequiredProperty = value;
+        return *this;
+    }
+
   private:
     OperationType operationTypeProperty = {};
     std::string idProperty = "MetricId";
@@ -87,6 +98,7 @@
         CollectionDuration(Milliseconds(0u));
     std::vector<std::pair<Milliseconds, double>> readingsProperty = {};
     std::pair<Milliseconds, double> expectedReadingProperty = {};
+    bool expectedIsTimerRequiredProperty = true;
 };
 
 inline std::ostream& operator<<(std::ostream& os, const MetricParams& mp)
@@ -103,6 +115,8 @@
     }
 
     auto [timestamp, reading] = mp.expectedReading();
-    os << " }, expected: " << reading << "(" << timestamp.count() << "ms) }";
+    os << " }, expectedReading: " << reading << "(" << timestamp.count()
+       << "ms), expectedIsTimerRequired: " << std::boolalpha
+       << mp.expectedIsTimerRequired() << " }";
     return os;
 }
diff --git a/tests/src/test_ensure.cpp b/tests/src/test_ensure.cpp
new file mode 100644
index 0000000..b604538
--- /dev/null
+++ b/tests/src/test_ensure.cpp
@@ -0,0 +1,52 @@
+#include "utils/ensure.hpp"
+
+#include <gmock/gmock.h>
+
+using namespace testing;
+
+class TestEnsure : public Test
+{
+  public:
+    utils::Ensure<std::function<void()>> makeEnsure()
+    {
+        return [this] { ++executed; };
+    }
+
+    utils::Ensure<std::function<void()>> sut;
+    size_t executed = 0u;
+};
+
+TEST_F(TestEnsure, executesCallbackOnceWhenDestroyed)
+{
+    sut = makeEnsure();
+    sut = nullptr;
+
+    EXPECT_THAT(executed, Eq(1u));
+}
+
+TEST_F(TestEnsure, executesCallbackOnceWhenMoved)
+{
+    sut = makeEnsure();
+    auto copy = std::move(sut);
+    copy = nullptr;
+
+    EXPECT_THAT(executed, Eq(1u));
+}
+
+TEST_F(TestEnsure, executesCallbackTwiceWhenReplaced)
+{
+    sut = makeEnsure();
+    sut = makeEnsure();
+    sut = nullptr;
+
+    EXPECT_THAT(executed, Eq(2u));
+}
+
+TEST_F(TestEnsure, executesCallbackTwiceWhenNewCallbackAssigned)
+{
+    sut = makeEnsure();
+    sut = [this] { executed += 10; };
+    sut = nullptr;
+
+    EXPECT_THAT(executed, Eq(11u));
+}
diff --git a/tests/src/test_metric.cpp b/tests/src/test_metric.cpp
index 31eabc6..f30b4f3 100644
--- a/tests/src/test_metric.cpp
+++ b/tests/src/test_metric.cpp
@@ -1,6 +1,7 @@
 #include "fakes/clock_fake.hpp"
 #include "helpers.hpp"
 #include "metric.hpp"
+#include "mocks/metric_listener_mock.hpp"
 #include "mocks/sensor_mock.hpp"
 #include "params/metric_params.hpp"
 #include "utils/conv_container.hpp"
@@ -55,6 +56,7 @@
     std::vector<std::shared_ptr<SensorMock>> sensorMocks = makeSensorMocks(1u);
     std::unique_ptr<ClockFake> clockFakePtr = std::make_unique<ClockFake>();
     ClockFake& clockFake = *clockFakePtr;
+    NiceMock<MetricListenerMock> listenerMock;
     std::shared_ptr<Metric> sut;
 };
 
@@ -90,6 +92,34 @@
                 ElementsAre(MetricValue({"id", "metadata", 0., 0u})));
 }
 
+TEST_F(TestMetric,
+       notifiesRegisteredListenersOnManualUpdateWhenMetricValueChanges)
+{
+    sut = makeSut(params.collectionTimeScope(CollectionTimeScope::startup));
+    sut->sensorUpdated(*sensorMocks.front(), Milliseconds{18}, 31.2);
+    sut->registerForUpdates(listenerMock);
+
+    EXPECT_CALL(listenerMock, metricUpdated()).Times(2);
+
+    sut->updateReadings(Milliseconds{50u});
+    sut->updateReadings(Milliseconds{100u});
+}
+
+TEST_F(TestMetric,
+       doesntNotifyRegisteredListenersOnManualUpdateWhenMetricValueDoesntChange)
+{
+    sut = makeSut(params.collectionTimeScope(CollectionTimeScope::startup)
+                      .operationType(OperationType::max));
+    sut->sensorUpdated(*sensorMocks.front(), Milliseconds{18}, 31.2);
+    sut->registerForUpdates(listenerMock);
+
+    EXPECT_CALL(listenerMock, metricUpdated()).Times(0);
+
+    sut->updateReadings(Milliseconds{50u});
+    sut->sensorUpdated(*sensorMocks.front(), Milliseconds{180}, 11.);
+    sut->updateReadings(Milliseconds{100u});
+}
+
 class TestMetricAfterInitialization : public TestMetric
 {
   public:
@@ -122,8 +152,6 @@
        throwsWhenUpdateIsPerformedOnUnknownSensor)
 {
     auto sensor = std::make_shared<StrictMock<SensorMock>>();
-    EXPECT_THROW(sut->sensorUpdated(*sensor, Milliseconds{10}),
-                 std::out_of_range);
     EXPECT_THROW(sut->sensorUpdated(*sensor, Milliseconds{10}, 20.0),
                  std::out_of_range);
 }
@@ -150,6 +178,33 @@
     EXPECT_THAT(conf, Eq(expected));
 }
 
+TEST_F(TestMetricAfterInitialization, notifiesRegisteredListeners)
+{
+    EXPECT_CALL(listenerMock, metricUpdated());
+
+    sut->registerForUpdates(listenerMock);
+    sut->sensorUpdated(*sensorMocks.front(), Milliseconds{18}, 31.2);
+}
+
+TEST_F(TestMetricAfterInitialization,
+       doesntNotifyRegisteredListenersWhenValueDoesntChange)
+{
+    EXPECT_CALL(listenerMock, metricUpdated());
+
+    sut->registerForUpdates(listenerMock);
+    sut->sensorUpdated(*sensorMocks.front(), Milliseconds{18}, 31.2);
+    sut->sensorUpdated(*sensorMocks.front(), Milliseconds{70}, 31.2);
+}
+
+TEST_F(TestMetricAfterInitialization, doesntNotifyAfterUnRegisterListener)
+{
+    EXPECT_CALL(listenerMock, metricUpdated()).Times(0);
+
+    sut->registerForUpdates(listenerMock);
+    sut->unregisterFromUpdates(listenerMock);
+    sut->sensorUpdated(*sensorMocks.front(), Milliseconds{18}, 31.2);
+}
+
 class TestMetricCalculationFunctions :
     public TestMetric,
     public WithParamInterface<MetricParams>
@@ -182,8 +237,9 @@
 
 MetricParams defaultPointParams()
 {
-    return defaultCollectionFunctionParams().collectionTimeScope(
-        CollectionTimeScope::point);
+    return defaultCollectionFunctionParams()
+        .collectionTimeScope(CollectionTimeScope::point)
+        .expectedIsTimerRequired(false);
 }
 
 INSTANTIATE_TEST_SUITE_P(
@@ -210,7 +266,8 @@
                .expectedReading(systemTimestamp + 16ms, 7.0),
            defaultMinParams()
                .collectionTimeScope(CollectionTimeScope::startup)
-               .expectedReading(systemTimestamp + 16ms, 3.0)));
+               .expectedReading(systemTimestamp + 16ms, 3.0)
+               .expectedIsTimerRequired(false)));
 
 MetricParams defaultMaxParams()
 {
@@ -233,7 +290,8 @@
                .expectedReading(systemTimestamp + 16ms, 7.0),
            defaultMaxParams()
                .collectionTimeScope(CollectionTimeScope::startup)
-               .expectedReading(systemTimestamp + 16ms, 14.0)));
+               .expectedReading(systemTimestamp + 16ms, 14.0)
+               .expectedIsTimerRequired(false)));
 
 MetricParams defaultSumParams()
 {
@@ -324,3 +382,9 @@
                 ElementsAre(MetricValue{"id", "metadata", expectedReading,
                                         expectedTimestamp.count()}));
 }
+
+TEST_P(TestMetricCalculationFunctions, returnsIsTimerRequired)
+{
+    EXPECT_THAT(sut->isTimerRequired(),
+                Eq(GetParam().expectedIsTimerRequired()));
+}
diff --git a/tests/src/test_report.cpp b/tests/src/test_report.cpp
index 9afa421..7646230 100644
--- a/tests/src/test_report.cpp
+++ b/tests/src/test_report.cpp
@@ -27,11 +27,24 @@
 
 constexpr Milliseconds systemTimestamp = 55ms;
 
+namespace
+{
+
+ReportParams defaultParams()
+{
+    return ReportParams();
+}
+
+ReportParams defaultOnChangeParams()
+{
+    return defaultParams().reportingType(ReportingType::onChange);
+}
+
+} // namespace
+
 class TestReport : public Test
 {
   public:
-    ReportParams defaultParams;
-
     std::unique_ptr<ReportManagerMock> reportManagerMock =
         std::make_unique<NiceMock<ReportManagerMock>>();
     std::unique_ptr<ReportFactoryMock> reportFactoryMock =
@@ -92,7 +105,7 @@
 
     void SetUp() override
     {
-        sut = makeReport(ReportParams());
+        sut = makeReport(defaultParams());
     }
 
     static interfaces::JsonStorage::FilePath to_file_path(std::string id)
@@ -157,39 +170,39 @@
 
 TEST_F(TestReport, returnsId)
 {
-    EXPECT_THAT(sut->getId(), Eq(defaultParams.reportId()));
+    EXPECT_THAT(sut->getId(), Eq(defaultParams().reportId()));
 }
 
 TEST_F(TestReport, verifyIfPropertiesHaveValidValue)
 {
     EXPECT_THAT(getProperty<bool>(sut->getPath(), "Enabled"),
-                Eq(defaultParams.enabled()));
+                Eq(defaultParams().enabled()));
     EXPECT_THAT(getProperty<uint64_t>(sut->getPath(), "Interval"),
-                Eq(defaultParams.interval().count()));
+                Eq(defaultParams().interval().count()));
     EXPECT_THAT(getProperty<bool>(sut->getPath(), "Persistency"), Eq(true));
     EXPECT_THAT(
         getProperty<std::vector<std::string>>(sut->getPath(), "ReportActions"),
-        Eq(utils::transform(defaultParams.reportActions(), [](const auto v) {
+        Eq(utils::transform(defaultParams().reportActions(), [](const auto v) {
             return utils::enumToString(v);
         })));
     EXPECT_THAT(getProperty<bool>(sut->getPath(), "EmitsReadingsUpdate"),
-                Eq(utils::contains(defaultParams.reportActions(),
+                Eq(utils::contains(defaultParams().reportActions(),
                                    ReportAction::emitsReadingsUpdate)));
     EXPECT_THAT(getProperty<uint64_t>(sut->getPath(), "AppendLimit"),
-                Eq(defaultParams.appendLimit()));
+                Eq(defaultParams().appendLimit()));
     EXPECT_THAT(getProperty<std::string>(sut->getPath(), "ReportingType"),
-                Eq(utils::enumToString(defaultParams.reportingType())));
+                Eq(utils::enumToString(defaultParams().reportingType())));
     EXPECT_THAT(getProperty<std::string>(sut->getPath(), "ReportUpdates"),
-                Eq(utils::enumToString(defaultParams.reportUpdates())));
+                Eq(utils::enumToString(defaultParams().reportUpdates())));
     EXPECT_THAT(
         getProperty<bool>(sut->getPath(), "LogToMetricReportsCollection"),
-        Eq(utils::contains(defaultParams.reportActions(),
+        Eq(utils::contains(defaultParams().reportActions(),
                            ReportAction::logToMetricReportsCollection)));
     EXPECT_THAT(getProperty<ReadingParameters>(
                     sut->getPath(), "ReadingParametersFutureVersion"),
-                Eq(toReadingParameters(defaultParams.metricParameters())));
+                Eq(toReadingParameters(defaultParams().metricParameters())));
     EXPECT_THAT(getProperty<std::string>(sut->getPath(), "Name"),
-                Eq(defaultParams.reportName()));
+                Eq(defaultParams().reportName()));
     EXPECT_THAT(
         getProperty<std::vector<std::string>>(sut->getPath(), "TriggerIds"),
         Eq(std::vector<std::string>()));
@@ -228,7 +241,7 @@
 TEST_F(TestReport, setReportingTypeWithValidNewType)
 {
     std::string newType = "Periodic";
-    std::string currType = utils::enumToString(defaultParams.reportingType());
+    std::string currType = utils::enumToString(defaultParams().reportingType());
 
     EXPECT_THAT(newType, Ne(currType));
     EXPECT_THAT(setProperty(sut->getPath(), "ReportingType", newType).value(),
@@ -240,7 +253,7 @@
 TEST_F(TestReport, setReportingTypeWithInvalidType)
 {
     std::string newType = "Periodic_ABC";
-    std::string prevType = utils::enumToString(defaultParams.reportingType());
+    std::string prevType = utils::enumToString(defaultParams().reportingType());
 
     EXPECT_THAT(setProperty(sut->getPath(), "ReportingType", newType).value(),
                 Eq(boost::system::errc::invalid_argument));
@@ -252,7 +265,7 @@
 {
     std::vector<std::string> newActions = {"EmitsReadingsUpdate"};
     std::vector<std::string> currActions =
-        utils::transform(defaultParams.reportActions(),
+        utils::transform(defaultParams().reportActions(),
                          [](const auto v) { return utils::enumToString(v); });
 
     EXPECT_THAT(newActions, Ne(currActions));
@@ -272,7 +285,7 @@
     std::vector<std::string> expectedActions = {"EmitsReadingsUpdate",
                                                 "LogToMetricReportsCollection"};
     std::vector<std::string> currActions =
-        utils::transform(defaultParams.reportActions(),
+        utils::transform(defaultParams().reportActions(),
                          [](const auto v) { return utils::enumToString(v); });
 
     EXPECT_THAT(newActions, Ne(currActions));
@@ -289,7 +302,7 @@
     std::vector<std::string> newActions = {};
     std::vector<std::string> expectedActions = {"LogToMetricReportsCollection"};
     std::vector<std::string> currActions =
-        utils::transform(defaultParams.reportActions(),
+        utils::transform(defaultParams().reportActions(),
                          [](const auto v) { return utils::enumToString(v); });
 
     EXPECT_THAT(newActions, Ne(currActions));
@@ -309,7 +322,7 @@
         Eq(boost::system::errc::invalid_argument));
     EXPECT_THAT(
         getProperty<std::vector<std::string>>(sut->getPath(), "ReportActions"),
-        Eq(utils::transform(defaultParams.reportActions(), [](const auto v) {
+        Eq(utils::transform(defaultParams().reportActions(), [](const auto v) {
             return utils::enumToString(v);
         })));
 }
@@ -344,7 +357,7 @@
 
 TEST_F(TestReport, setEnabledWithNewValue)
 {
-    bool newValue = !defaultParams.enabled();
+    bool newValue = !defaultParams().enabled();
     EXPECT_THAT(setProperty(sut->getPath(), "Enabled", newValue).value(),
                 Eq(boost::system::errc::success));
     EXPECT_THAT(getProperty<bool>(sut->getPath(), "Enabled"), Eq(newValue));
@@ -352,7 +365,7 @@
 
 TEST_F(TestReport, setIntervalWithValidValue)
 {
-    uint64_t newValue = defaultParams.interval().count() + 1;
+    uint64_t newValue = defaultParams().interval().count() + 1;
     EXPECT_THAT(setProperty(sut->getPath(), "Interval", newValue).value(),
                 Eq(boost::system::errc::success));
     EXPECT_THAT(getProperty<uint64_t>(sut->getPath(), "Interval"),
@@ -363,11 +376,11 @@
     TestReport,
     settingIntervalWithInvalidValueDoesNotChangePropertyAndReturnsInvalidArgument)
 {
-    uint64_t newValue = defaultParams.interval().count() - 1;
+    uint64_t newValue = defaultParams().interval().count() - 1;
     EXPECT_THAT(setProperty(sut->getPath(), "Interval", newValue).value(),
                 Eq(boost::system::errc::invalid_argument));
     EXPECT_THAT(getProperty<uint64_t>(sut->getPath(), "Interval"),
-                Eq(defaultParams.interval().count()));
+                Eq(defaultParams().interval().count()));
 }
 
 TEST_F(TestReport, settingEmitsReadingsUpdateHaveNoEffect)
@@ -376,7 +389,7 @@
         setProperty(sut->getPath(), "EmitsReadingsUpdate", true).value(),
         Eq(boost::system::errc::read_only_file_system));
     EXPECT_THAT(getProperty<bool>(sut->getPath(), "EmitsReadingsUpdate"),
-                Eq(utils::contains(defaultParams.reportActions(),
+                Eq(utils::contains(defaultParams().reportActions(),
                                    ReportAction::emitsReadingsUpdate)));
 }
 
@@ -388,7 +401,7 @@
         Eq(boost::system::errc::read_only_file_system));
     EXPECT_THAT(
         getProperty<bool>(sut->getPath(), "LogToMetricReportsCollection"),
-        Eq(utils::contains(defaultParams.reportActions(),
+        Eq(utils::contains(defaultParams().reportActions(),
                            ReportAction::logToMetricReportsCollection)));
 }
 
@@ -428,15 +441,15 @@
     utils::Messanger messanger(DbusEnvironment::getIoc());
 
     messanger.send(messages::TriggerPresenceChangedInd{
-        messages::Presence::Exist, "trigger1", {defaultParams.reportId()}});
+        messages::Presence::Exist, "trigger1", {defaultParams().reportId()}});
     messanger.send(messages::TriggerPresenceChangedInd{
-        messages::Presence::Exist, "trigger1", {defaultParams.reportId()}});
+        messages::Presence::Exist, "trigger1", {defaultParams().reportId()}});
     messanger.send(messages::TriggerPresenceChangedInd{
         messages::Presence::Exist, "trigger2", {"someOtherReport"}});
     messanger.send(messages::TriggerPresenceChangedInd{
         messages::Presence::Exist,
         "trigger3",
-        {"someOtherReport", defaultParams.reportId()}});
+        {"someOtherReport", defaultParams().reportId()}});
 
     EXPECT_THAT(
         getProperty<std::vector<std::string>>(sut->getPath(), "TriggerIds"),
@@ -448,18 +461,18 @@
     utils::Messanger messanger(DbusEnvironment::getIoc());
 
     messanger.send(messages::TriggerPresenceChangedInd{
-        messages::Presence::Exist, "trigger1", {defaultParams.reportId()}});
+        messages::Presence::Exist, "trigger1", {defaultParams().reportId()}});
     messanger.send(messages::TriggerPresenceChangedInd{
-        messages::Presence::Exist, "trigger2", {defaultParams.reportId()}});
+        messages::Presence::Exist, "trigger2", {defaultParams().reportId()}});
     messanger.send(messages::TriggerPresenceChangedInd{
-        messages::Presence::Exist, "trigger3", {defaultParams.reportId()}});
+        messages::Presence::Exist, "trigger3", {defaultParams().reportId()}});
 
     messanger.send(messages::TriggerPresenceChangedInd{
-        messages::Presence::Removed, "trigger1", {defaultParams.reportId()}});
+        messages::Presence::Removed, "trigger1", {defaultParams().reportId()}});
     messanger.send(messages::TriggerPresenceChangedInd{
         messages::Presence::Removed, "trigger2", {}});
     messanger.send(messages::TriggerPresenceChangedInd{
-        messages::Presence::Removed, "trigger1", {defaultParams.reportId()}});
+        messages::Presence::Removed, "trigger1", {defaultParams().reportId()}});
 
     EXPECT_THAT(
         getProperty<std::vector<std::string>>(sut->getPath(), "TriggerIds"),
@@ -471,18 +484,18 @@
     utils::Messanger messanger(DbusEnvironment::getIoc());
 
     messanger.send(messages::TriggerPresenceChangedInd{
-        messages::Presence::Exist, "trigger1", {defaultParams.reportId()}});
+        messages::Presence::Exist, "trigger1", {defaultParams().reportId()}});
     messanger.send(messages::TriggerPresenceChangedInd{
-        messages::Presence::Exist, "trigger2", {defaultParams.reportId()}});
+        messages::Presence::Exist, "trigger2", {defaultParams().reportId()}});
     messanger.send(messages::TriggerPresenceChangedInd{
-        messages::Presence::Exist, "trigger3", {defaultParams.reportId()}});
+        messages::Presence::Exist, "trigger3", {defaultParams().reportId()}});
 
     messanger.send(messages::TriggerPresenceChangedInd{
-        messages::Presence::Exist, "trigger1", {defaultParams.reportId()}});
+        messages::Presence::Exist, "trigger1", {defaultParams().reportId()}});
     messanger.send(messages::TriggerPresenceChangedInd{
         messages::Presence::Exist, "trigger2", {}});
     messanger.send(messages::TriggerPresenceChangedInd{
-        messages::Presence::Exist, "trigger3", {defaultParams.reportId()}});
+        messages::Presence::Exist, "trigger3", {defaultParams().reportId()}});
 
     EXPECT_THAT(
         getProperty<std::vector<std::string>>(sut->getPath(), "TriggerIds"),
@@ -502,49 +515,49 @@
 
 INSTANTIATE_TEST_SUITE_P(
     _, TestReportStore,
-    Values(std::make_pair("Enabled"s, nlohmann::json(ReportParams().enabled())),
-           std::make_pair("Version"s, nlohmann::json(6)),
-           std::make_pair("Id"s, nlohmann::json(ReportParams().reportId())),
-           std::make_pair("Name"s, nlohmann::json(ReportParams().reportName())),
-           std::make_pair("ReportingType",
-                          nlohmann::json(ReportParams().reportingType())),
-           std::make_pair("ReportActions", nlohmann::json(utils::transform(
-                                               ReportParams().reportActions(),
-                                               [](const auto v) {
-                                                   return utils::toUnderlying(
-                                                       v);
-                                               }))),
-           std::make_pair("Interval",
-                          nlohmann::json(ReportParams().interval().count())),
-           std::make_pair("AppendLimit",
-                          nlohmann::json(ReportParams().appendLimit())),
-           std::make_pair(
-               "ReadingParameters",
-               nlohmann::json(
-                   {{{tstring::SensorPath::str(),
-                      {{{tstring::Service::str(), "Service"},
-                        {tstring::Path::str(),
-                         "/xyz/openbmc_project/sensors/power/p1"},
-                        {tstring::Metadata::str(), "metadata1"}}}},
-                     {tstring::OperationType::str(), OperationType::avg},
-                     {tstring::Id::str(), "MetricId1"},
-                     {tstring::CollectionTimeScope::str(),
-                      CollectionTimeScope::point},
-                     {tstring::CollectionDuration::str(), 0}},
-                    {{tstring::SensorPath::str(),
-                      {{{tstring::Service::str(), "Service"},
-                        {tstring::Path::str(),
-                         "/xyz/openbmc_project/sensors/power/p2"},
-                        {tstring::Metadata::str(), "metadata2"}}}},
-                     {tstring::OperationType::str(), OperationType::avg},
-                     {tstring::Id::str(), "MetricId2"},
-                     {tstring::CollectionTimeScope::str(),
-                      CollectionTimeScope::point},
-                     {tstring::CollectionDuration::str(), 0}}}))));
+    Values(
+        std::make_pair("Enabled"s, nlohmann::json(defaultParams().enabled())),
+        std::make_pair("Version"s, nlohmann::json(6)),
+        std::make_pair("Id"s, nlohmann::json(defaultParams().reportId())),
+        std::make_pair("Name"s, nlohmann::json(defaultParams().reportName())),
+        std::make_pair("ReportingType",
+                       nlohmann::json(defaultParams().reportingType())),
+        std::make_pair("ReportActions", nlohmann::json(utils::transform(
+                                            defaultParams().reportActions(),
+                                            [](const auto v) {
+                                                return utils::toUnderlying(v);
+                                            }))),
+        std::make_pair("Interval",
+                       nlohmann::json(defaultParams().interval().count())),
+        std::make_pair("AppendLimit",
+                       nlohmann::json(ReportParams().appendLimit())),
+        std::make_pair(
+            "ReadingParameters",
+            nlohmann::json(
+                {{{tstring::SensorPath::str(),
+                   {{{tstring::Service::str(), "Service"},
+                     {tstring::Path::str(),
+                      "/xyz/openbmc_project/sensors/power/p1"},
+                     {tstring::Metadata::str(), "metadata1"}}}},
+                  {tstring::OperationType::str(), OperationType::avg},
+                  {tstring::Id::str(), "MetricId1"},
+                  {tstring::CollectionTimeScope::str(),
+                   CollectionTimeScope::point},
+                  {tstring::CollectionDuration::str(), 0}},
+                 {{tstring::SensorPath::str(),
+                   {{{tstring::Service::str(), "Service"},
+                     {tstring::Path::str(),
+                      "/xyz/openbmc_project/sensors/power/p2"},
+                     {tstring::Metadata::str(), "metadata2"}}}},
+                  {tstring::OperationType::str(), OperationType::avg},
+                  {tstring::Id::str(), "MetricId2"},
+                  {tstring::CollectionTimeScope::str(),
+                   CollectionTimeScope::point},
+                  {tstring::CollectionDuration::str(), 0}}}))));
 
 TEST_P(TestReportStore, settingPersistencyToTrueStoresReport)
 {
-    sut = makeReport(ReportParams());
+    sut = makeReport(defaultParams());
 
     {
         InSequence seq;
@@ -565,10 +578,10 @@
 
 TEST_P(TestReportStore, reportIsSavedToStorageAfterCreated)
 {
-    EXPECT_CALL(storageMock, store(to_file_path(ReportParams().reportId()), _))
+    EXPECT_CALL(storageMock, store(to_file_path(defaultParams().reportId()), _))
         .WillOnce(SaveArg<1>(&storedConfiguration));
 
-    sut = makeReport(ReportParams());
+    sut = makeReport(defaultParams());
 
     const auto& [key, value] = GetParam();
 
@@ -586,9 +599,9 @@
 
 INSTANTIATE_TEST_SUITE_P(
     ValidNames, TestReportValidNames,
-    Values(ReportParams().reportName("Valid_1"),
-           ReportParams().reportName("Valid_1/Valid_2"),
-           ReportParams().reportName("Valid_1/Valid_2/Valid_3")));
+    Values(defaultParams().reportName("Valid_1"),
+           defaultParams().reportName("Valid_1/Valid_2"),
+           defaultParams().reportName("Valid_1/Valid_2/Valid_3")));
 
 TEST_P(TestReportValidNames, reportCtorDoesNotThrowOnValidName)
 {
@@ -605,11 +618,11 @@
 };
 
 INSTANTIATE_TEST_SUITE_P(InvalidNames, TestReportInvalidIds,
-                         Values(ReportParams().reportId("/"),
-                                ReportParams().reportId("/Invalid"),
-                                ReportParams().reportId("Invalid/"),
-                                ReportParams().reportId("Invalid/Invalid/"),
-                                ReportParams().reportId("Invalid?")));
+                         Values(defaultParams().reportId("/"),
+                                defaultParams().reportId("/Invalid"),
+                                defaultParams().reportId("Invalid/"),
+                                defaultParams().reportId("Invalid/Invalid/"),
+                                defaultParams().reportId("Invalid?")));
 
 TEST_P(TestReportInvalidIds, failsToCreateReportWithInvalidName)
 {
@@ -631,9 +644,9 @@
 
 INSTANTIATE_TEST_SUITE_P(
     _, TestReportAllReportTypes,
-    Values(ReportParams().reportingType(ReportingType::onRequest),
-           ReportParams().reportingType(ReportingType::onChange),
-           ReportParams().reportingType(ReportingType::periodic)));
+    Values(defaultParams().reportingType(ReportingType::onRequest),
+           defaultParams().reportingType(ReportingType::onChange),
+           defaultParams().reportingType(ReportingType::periodic)));
 
 TEST_P(TestReportAllReportTypes, returnPropertValueOfReportType)
 {
@@ -681,7 +694,7 @@
     void SetUp() override
     {
         sut =
-            makeReport(ReportParams().reportingType(ReportingType::onRequest));
+            makeReport(defaultParams().reportingType(ReportingType::onRequest));
     }
 };
 
@@ -721,8 +734,8 @@
 
 INSTANTIATE_TEST_SUITE_P(
     _, TestReportNonOnRequestType,
-    Values(ReportParams().reportingType(ReportingType::periodic),
-           ReportParams().reportingType(ReportingType::onChange)));
+    Values(defaultParams().reportingType(ReportingType::periodic),
+           defaultParams().reportingType(ReportingType::onChange)));
 
 TEST_P(TestReportNonOnRequestType, readingsAreNotUpdateOnUpdateCall)
 {
@@ -745,8 +758,8 @@
 
 INSTANTIATE_TEST_SUITE_P(
     _, TestReportNonPeriodicReport,
-    Values(ReportParams().reportingType(ReportingType::onRequest),
-           ReportParams().reportingType(ReportingType::onChange)));
+    Values(defaultParams().reportingType(ReportingType::onRequest),
+           defaultParams().reportingType(ReportingType::onChange)));
 
 TEST_P(TestReportNonPeriodicReport, readingsAreNotUpdatedAfterIntervalExpires)
 {
@@ -760,7 +773,8 @@
 {
     void SetUp() override
     {
-        sut = makeReport(ReportParams().reportingType(ReportingType::periodic));
+        sut =
+            makeReport(defaultParams().reportingType(ReportingType::periodic));
     }
 };
 
@@ -810,7 +824,7 @@
     _, TestReportWithReportUpdatesAndLimit,
     Values(
         ReportUpdatesReportParams{
-            ReportParams()
+            defaultParams()
                 .reportUpdates(ReportUpdates::appendWrapsWhenFull)
                 .appendLimit(5),
             std::vector<ReadingData>{{std::make_tuple("aa"s, "bb"s, 42.0, 74u),
@@ -820,7 +834,7 @@
                                       std::make_tuple("a"s, "b"s, 17.1, 114u)}},
             true},
         ReportUpdatesReportParams{
-            ReportParams()
+            defaultParams()
                 .reportUpdates(ReportUpdates::appendWrapsWhenFull)
                 .appendLimit(4),
             std::vector<ReadingData>{
@@ -830,12 +844,12 @@
                  std::make_tuple("aa"s, "bb"s, 42.0, 74u)}},
             true},
         ReportUpdatesReportParams{
-            ReportParams()
+            defaultParams()
                 .reportUpdates(ReportUpdates::appendWrapsWhenFull)
                 .appendLimit(0),
             std::vector<ReadingData>{}, true},
         ReportUpdatesReportParams{
-            ReportParams()
+            defaultParams()
                 .reportUpdates(ReportUpdates::appendStopsWhenFull)
                 .appendLimit(10),
             std::vector<ReadingData>{
@@ -849,7 +863,7 @@
                  std::make_tuple("aa"s, "bb"s, 42.0, 74u)}},
             true},
         ReportUpdatesReportParams{
-            ReportParams()
+            defaultParams()
                 .reportUpdates(ReportUpdates::appendStopsWhenFull)
                 .appendLimit(5),
             std::vector<ReadingData>{{std::make_tuple("a"s, "b"s, 17.1, 114u),
@@ -859,7 +873,7 @@
                                       std::make_tuple("a"s, "b"s, 17.1, 114u)}},
             false},
         ReportUpdatesReportParams{
-            ReportParams()
+            defaultParams()
                 .reportUpdates(ReportUpdates::appendStopsWhenFull)
                 .appendLimit(4),
             std::vector<ReadingData>{
@@ -869,12 +883,12 @@
                  std::make_tuple("aa"s, "bb"s, 42.0, 74u)}},
             false},
         ReportUpdatesReportParams{
-            ReportParams()
+            defaultParams()
                 .reportUpdates(ReportUpdates::appendStopsWhenFull)
                 .appendLimit(0),
             std::vector<ReadingData>{}, false},
         ReportUpdatesReportParams{
-            ReportParams()
+            defaultParams()
                 .reportUpdates(ReportUpdates::overwrite)
                 .appendLimit(500),
             std::vector<ReadingData>{
@@ -882,7 +896,7 @@
                  std::make_tuple("aa"s, "bb"s, 42.0, 74u)}},
             true},
         ReportUpdatesReportParams{
-            ReportParams()
+            defaultParams()
                 .reportUpdates(ReportUpdates::overwrite)
                 .appendLimit(1),
             std::vector<ReadingData>{
@@ -890,7 +904,7 @@
                  std::make_tuple("aa"s, "bb"s, 42.0, 74u)}},
             true},
         ReportUpdatesReportParams{
-            ReportParams()
+            defaultParams()
                 .reportUpdates(ReportUpdates::overwrite)
                 .appendLimit(0),
             std::vector<ReadingData>{
@@ -918,7 +932,9 @@
 {
   public:
     void SetUp() override
-    {}
+    {
+        initMetricMocks(defaultParams().metricParameters());
+    }
 
     void monitorProc(sdbusplus::message::message& msg)
     {
@@ -955,25 +971,60 @@
 };
 
 TEST_F(TestReportInitialization,
-       metricsAreInitializedWhenEnabledReportConstructed)
+       registersForMetricUpdatesWhenOnChangeReportCreated)
 {
-    initMetricMocks(defaultParams.metricParameters());
+    std::vector<const interfaces::MetricListener*> args;
     for (auto& metric : metricMocks)
     {
-        EXPECT_CALL(*metric, initialize()).Times(1);
+        EXPECT_CALL(*metric, registerForUpdates(_))
+            .WillOnce(Invoke([&args](const interfaces::MetricListener& report) {
+                args.emplace_back(&report);
+            }));
+        ;
     }
-    sut = makeReport(defaultParams.enabled(true));
+
+    sut = makeReport(defaultParams().reportingType(ReportingType::onChange));
+
+    EXPECT_THAT(args, SizeIs(metricMocks.size()));
+    for (const auto* reportPtr : args)
+    {
+        EXPECT_THAT(reportPtr, Eq(sut.get()));
+    }
+}
+
+TEST_F(TestReportInitialization,
+       deregistersForMetricUpdatesWhenOnChangeReportDestroyed)
+{
+    sut = makeReport(defaultParams().reportingType(ReportingType::onChange));
+
+    for (auto& metric : metricMocks)
+    {
+        EXPECT_CALL(*metric,
+                    unregisterFromUpdates(Ref(
+                        static_cast<interfaces::MetricListener&>(*sut.get()))));
+    }
+
+    sut = nullptr;
+}
+
+TEST_F(TestReportInitialization,
+       metricsAreInitializedWhenEnabledReportConstructed)
+{
+    for (auto& metric : metricMocks)
+    {
+        EXPECT_CALL(*metric, initialize());
+    }
+    sut = makeReport(defaultParams().enabled(true));
 }
 
 TEST_F(TestReportInitialization,
        metricsAreNotInitializedWhenDisabledReportConstructed)
 {
-    initMetricMocks(defaultParams.metricParameters());
     for (auto& metric : metricMocks)
     {
         EXPECT_CALL(*metric, initialize()).Times(0);
     }
-    sut = makeReport(defaultParams.enabled(false));
+    sut = makeReport(defaultParams().enabled(false));
 }
 
 TEST_F(TestReportInitialization,
@@ -985,14 +1036,15 @@
 
     const auto elapsed = DbusEnvironment::measureTime([this] {
         sut =
-            makeReport(defaultParams.reportingType(ReportingType::periodic)
+            makeReport(defaultParams()
+                           .reportingType(ReportingType::periodic)
                            .reportActions({ReportAction::emitsReadingsUpdate}));
         makeMonitor();
         EXPECT_TRUE(DbusEnvironment::waitForFuture("readingsUpdated"));
     });
 
-    EXPECT_THAT(elapsed, AllOf(Ge(defaultParams.interval()),
-                               Lt(defaultParams.interval() * 2)));
+    EXPECT_THAT(elapsed, AllOf(Ge(defaultParams().interval()),
+                               Lt(defaultParams().interval() * 2)));
 }
 
 TEST_F(TestReportInitialization,
@@ -1000,16 +1052,17 @@
 {
     EXPECT_CALL(readingsUpdated, Call()).Times(0);
 
-    sut = makeReport(
-        defaultParams.reportingType(ReportingType::periodic).reportActions({}));
+    sut = makeReport(defaultParams()
+                         .reportingType(ReportingType::periodic)
+                         .reportActions({}));
     makeMonitor();
-    DbusEnvironment::sleepFor(defaultParams.interval() * 2);
+    DbusEnvironment::sleepFor(defaultParams().interval() * 2);
 }
 
 TEST_F(TestReportInitialization, appendLimitDeducedProperly)
 {
     sut = makeReport(
-        ReportParams().appendLimit(std::numeric_limits<uint64_t>::max()));
+        defaultParams().appendLimit(std::numeric_limits<uint64_t>::max()));
     auto appendLimit = getProperty<uint64_t>(sut->getPath(), "AppendLimit");
     EXPECT_EQ(appendLimit, 2ull);
 }
@@ -1044,3 +1097,41 @@
         getProperty<std::vector<std::string>>(sut->getPath(), "TriggerIds"),
         UnorderedElementsAre("trigger1", "trigger2"));
 }
+
+class TestReportInitializationOnChangeReport : public TestReportInitialization
+{
+  public:
+    void SetUp() override
+    {
+        initMetricMocks(params.metricParameters());
+    }
+
+    ReportParams params = defaultOnChangeParams();
+};
+
+TEST_F(TestReportInitializationOnChangeReport,
+       doesntUpdateReadingsWhenNotRequired)
+{
+    EXPECT_CALL(*metricMocks[0], updateReadings(_)).Times(0);
+
+    ON_CALL(*metricMocks[0], isTimerRequired()).WillByDefault(Return(false));
+
+    sut = makeReport(params);
+
+    DbusEnvironment::sleepFor(500ms);
+}
+
+TEST_F(TestReportInitializationOnChangeReport, updatesReadingsWhenRequired)
+{
+    EXPECT_CALL(*metricMocks[0], updateReadings(_))
+        .WillOnce(Return())
+        .WillOnce(
+            InvokeWithoutArgs(DbusEnvironment::setPromise("readingsUpdated")))
+        .WillRepeatedly(Return());
+
+    ON_CALL(*metricMocks[0], isTimerRequired()).WillByDefault(Return(true));
+
+    sut = makeReport(params);
+
+    DbusEnvironment::waitForFuture("readingsUpdated");
+}
diff --git a/tests/src/test_report_manager.cpp b/tests/src/test_report_manager.cpp
index f4ce184..55b5a3c 100644
--- a/tests/src/test_report_manager.cpp
+++ b/tests/src/test_report_manager.cpp
@@ -121,6 +121,19 @@
     EXPECT_THAT(path, Eq(reportMock.getPath()));
 }
 
+TEST_F(TestReportManager, addOnChangeReport)
+{
+    EXPECT_CALL(reportFactoryMock, convertMetricParams(_, _));
+    reportFactoryMock
+        .expectMake(reportParams.reportingType(ReportingType::onChange),
+                    Ref(*sut), Ref(storageMock))
+        .WillOnce(Return(ByMove(std::move(reportMockPtr))));
+
+    auto [ec, path] = addReport(reportParams);
+    EXPECT_THAT(ec.value(), Eq(boost::system::errc::success));
+    EXPECT_THAT(path, Eq(reportMock.getPath()));
+}
+
 TEST_F(TestReportManager, nameIsUsedToGenerateIdWhenIdIsEmptyInAddReport)
 {
     reportParams.reportId("ReportName");
diff --git a/tests/src/test_sensor.cpp b/tests/src/test_sensor.cpp
index c073ee7..8738bde 100644
--- a/tests/src/test_sensor.cpp
+++ b/tests/src/test_sensor.cpp
@@ -147,12 +147,9 @@
     ASSERT_TRUE(DbusEnvironment::waitForFuture("notify"));
 }
 
-TEST_F(TestSensorNotification, notifiesListenerWithValueWhenNoChangeOccurs)
+TEST_F(TestSensorNotification, doesntNotifyListenerWhenNoChangeOccurs)
 {
-    InSequence seq;
-
-    EXPECT_CALL(*listenerMock, sensorUpdated(Ref(*sut), Ge(timestamp), 42.7));
-    EXPECT_CALL(*listenerMock, sensorUpdated(Ref(*sut), Ge(timestamp)))
+    EXPECT_CALL(*listenerMock, sensorUpdated(Ref(*sut), Ge(timestamp), 42.7))
         .WillOnce(InvokeWithoutArgs(DbusEnvironment::setPromise("notify")));
 
     sensorObject->setValue(42.7);