diff --git a/redfish-core/ut/time_utils_test.cpp b/redfish-core/ut/time_utils_test.cpp
index 70999ce..86174ba 100644
--- a/redfish-core/ut/time_utils_test.cpp
+++ b/redfish-core/ut/time_utils_test.cpp
@@ -2,62 +2,51 @@
 
 #include <gmock/gmock.h>
 
-using namespace testing;
-
-class FromDurationTest :
-    public Test,
-    public WithParamInterface<
-        std::pair<std::string, std::optional<std::chrono::milliseconds>>>
-{};
-
-INSTANTIATE_TEST_SUITE_P(
-    _, FromDurationTest,
-    Values(std::make_pair("PT12S", std::chrono::milliseconds(12000)),
-           std::make_pair("PT0.204S", std::chrono::milliseconds(204)),
-           std::make_pair("PT0.2S", std::chrono::milliseconds(200)),
-           std::make_pair("PT50M", std::chrono::milliseconds(3000000)),
-           std::make_pair("PT23H", std::chrono::milliseconds(82800000)),
-           std::make_pair("P51D", std::chrono::milliseconds(4406400000)),
-           std::make_pair("PT2H40M10.1S", std::chrono::milliseconds(9610100)),
-           std::make_pair("P20DT2H40M10.1S",
-                          std::chrono::milliseconds(1737610100)),
-           std::make_pair("", std::chrono::milliseconds(0)),
-           std::make_pair("PTS", std::nullopt),
-           std::make_pair("P1T", std::nullopt),
-           std::make_pair("PT100M1000S100", std::nullopt),
-           std::make_pair("PDTHMS", std::nullopt),
-           std::make_pair("P99999999999999999DT", std::nullopt),
-           std::make_pair("PD222T222H222M222.222S", std::nullopt),
-           std::make_pair("PT99999H9999999999999999999999M99999999999S",
-                          std::nullopt),
-           std::make_pair("PT-9H", std::nullopt)));
-
-TEST_P(FromDurationTest, convertToMilliseconds)
+TEST(FromDurationTest, PositiveTests)
 {
-    const auto& [str, expected] = GetParam();
-    EXPECT_THAT(redfish::time_utils::fromDurationString(str), Eq(expected));
+    using redfish::time_utils::fromDurationString;
+    using std::chrono::milliseconds;
+    EXPECT_EQ(fromDurationString("PT12S"), milliseconds(12000));
+    EXPECT_EQ(fromDurationString("PT0.204S"), milliseconds(204));
+    EXPECT_EQ(fromDurationString("PT0.2S"), milliseconds(200));
+    EXPECT_EQ(fromDurationString("PT50M"), milliseconds(3000000));
+    EXPECT_EQ(fromDurationString("PT23H"), milliseconds(82800000));
+    EXPECT_EQ(fromDurationString("P51D"), milliseconds(4406400000));
+    EXPECT_EQ(fromDurationString("PT2H40M10.1S"), milliseconds(9610100));
+    EXPECT_EQ(fromDurationString("P20DT2H40M10.1S"), milliseconds(1737610100));
+    EXPECT_EQ(fromDurationString(""), milliseconds(0));
 }
 
-class ToDurationTest :
-    public Test,
-    public WithParamInterface<std::pair<std::chrono::milliseconds, std::string>>
-{};
-
-INSTANTIATE_TEST_SUITE_P(
-    _, ToDurationTest,
-    Values(std::make_pair(std::chrono::milliseconds(12000), "PT12.000S"),
-           std::make_pair(std::chrono::milliseconds(204), "PT0.204S"),
-           std::make_pair(std::chrono::milliseconds(200), "PT0.200S"),
-           std::make_pair(std::chrono::milliseconds(3000000), "PT50M"),
-           std::make_pair(std::chrono::milliseconds(82800000), "PT23H"),
-           std::make_pair(std::chrono::milliseconds(4406400000), "P51DT"),
-           std::make_pair(std::chrono::milliseconds(9610100), "PT2H40M10.100S"),
-           std::make_pair(std::chrono::milliseconds(1737610100),
-                          "P20DT2H40M10.100S"),
-           std::make_pair(std::chrono::milliseconds(-250), "")));
-
-TEST_P(ToDurationTest, convertToDuration)
+TEST(FromDurationTest, NegativeTests)
 {
-    const auto& [ms, expected] = GetParam();
-    EXPECT_THAT(redfish::time_utils::toDurationString(ms), Eq(expected));
+    using redfish::time_utils::fromDurationString;
+    EXPECT_EQ(fromDurationString("PTS"), std::nullopt);
+    EXPECT_EQ(fromDurationString("P1T"), std::nullopt);
+    EXPECT_EQ(fromDurationString("PT100M1000S100"), std::nullopt);
+    EXPECT_EQ(fromDurationString("PDTHMS"), std::nullopt);
+    EXPECT_EQ(fromDurationString("P99999999999999999DT"), std::nullopt);
+    EXPECT_EQ(fromDurationString("PD222T222H222M222.222S"), std::nullopt);
+    EXPECT_EQ(fromDurationString("PT99999H9999999999999999999999M99999999999S"),
+              std::nullopt);
+    EXPECT_EQ(fromDurationString("PT-9H"), std::nullopt);
+}
+TEST(ToDurationTest, PositiveTests)
+{
+    using redfish::time_utils::toDurationString;
+    using std::chrono::milliseconds;
+    EXPECT_EQ(toDurationString(milliseconds(12000)), "PT12.000S");
+    EXPECT_EQ(toDurationString(milliseconds(204)), "PT0.204S");
+    EXPECT_EQ(toDurationString(milliseconds(200)), "PT0.200S");
+    EXPECT_EQ(toDurationString(milliseconds(3000000)), "PT50M");
+    EXPECT_EQ(toDurationString(milliseconds(82800000)), "PT23H");
+    EXPECT_EQ(toDurationString(milliseconds(4406400000)), "P51DT");
+    EXPECT_EQ(toDurationString(milliseconds(9610100)), "PT2H40M10.100S");
+    EXPECT_EQ(toDurationString(milliseconds(1737610100)), "P20DT2H40M10.100S");
+}
+
+TEST(ToDurationTest, NegativeTests)
+{
+    using redfish::time_utils::toDurationString;
+    using std::chrono::milliseconds;
+    EXPECT_EQ(toDurationString(milliseconds(-250)), "");
 }