diff --git a/fsw/cfe-core/unit-test/es_UT.c b/fsw/cfe-core/unit-test/es_UT.c
index b0416ad2a..d78d7a20b 100644
--- a/fsw/cfe-core/unit-test/es_UT.c
+++ b/fsw/cfe-core/unit-test/es_UT.c
@@ -712,7 +712,7 @@ void TestStartupErrorPaths(void)
 
     /* Perform ES main startup with a mutex creation failure */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_MutSemCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_MutSemCreate), OS_ERROR);
     UT_SetReadBuffer(StartupScript, strlen(StartupScript));
     UT_SetDataBuffer(UT_KEY(CFE_PSP_Panic), &PanicStatus, sizeof(PanicStatus), false);
     CFE_ES_Main(CFE_PSP_RST_TYPE_POWERON, 1, 1,
@@ -726,7 +726,7 @@ void TestStartupErrorPaths(void)
     /* Perform ES main startup with a file open failure */
     ES_ResetUnitTest();
     UT_SetDummyFuncRtn(OS_SUCCESS);
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     UT_SetHookFunction(UT_KEY(OS_TaskCreate), ES_UT_SetAppStateHook, NULL);
     CFE_ES_Main(CFE_PSP_RST_TYPE_POWERON, 1, 1,
                 (char *) CFE_PLATFORM_ES_NONVOL_STARTUP_FILE);
@@ -860,9 +860,9 @@ void TestStartupErrorPaths(void)
      * following a failure to create the RAM volume
      */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_initfs), OS_ERROR);
-    UT_SetForceFail(UT_KEY(OS_mount), OS_ERROR);
-    UT_SetForceFail(UT_KEY(OS_mkfs), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_initfs), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_mount), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_mkfs), OS_ERROR);
     CFE_ES_InitializeFileSystems(CFE_PSP_RST_TYPE_POWERON);
     UT_Report(__FILE__, __LINE__,
               UT_PrintfIsInHistory(UT_OSP_MESSAGES[UT_OSP_CREATE_VOLATILE]) &&
@@ -875,9 +875,9 @@ void TestStartupErrorPaths(void)
      * following a failure to reformat the RAM volume
      */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_initfs), OS_ERROR);
-    UT_SetForceFail(UT_KEY(OS_mount), OS_ERROR);
-    UT_SetForceFail(UT_KEY(OS_mkfs), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_initfs), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_mount), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_mkfs), OS_ERROR);
     CFE_ES_InitializeFileSystems(CFE_PSP_RST_TYPE_PROCESSOR);
     UT_Report(__FILE__, __LINE__,
               UT_PrintfIsInHistory(UT_OSP_MESSAGES[UT_OSP_INSUFF_FREE_SPACE]) &&
@@ -893,7 +893,7 @@ void TestStartupErrorPaths(void)
      * following failure to get the volatile disk memory
      */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(CFE_PSP_GetVolatileDiskMem), CFE_PSP_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_PSP_GetVolatileDiskMem), CFE_PSP_ERROR);
     CFE_ES_InitializeFileSystems(CFE_PSP_RST_TYPE_PROCESSOR);
     UT_Report(__FILE__, __LINE__,
               UT_PrintfIsInHistory(UT_OSP_MESSAGES[UT_OSP_INSUFF_FREE_SPACE]) &&
@@ -905,7 +905,7 @@ void TestStartupErrorPaths(void)
      * reported is greater than the number of RAM disk sectors
      */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_mount), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_mount), OS_ERROR);
     UT_SetDeferredRetcode(UT_KEY(OS_fsBlocksFree), 1, CFE_PLATFORM_ES_RAM_DISK_NUM_SECTORS + 1);
     CFE_ES_InitializeFileSystems(CFE_PSP_RST_TYPE_PROCESSOR);
     UT_Report(__FILE__, __LINE__,
@@ -918,7 +918,7 @@ void TestStartupErrorPaths(void)
      * following a failure to remove the RAM volume
      */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_rmfs), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_rmfs), OS_ERROR);
     CFE_ES_InitializeFileSystems(CFE_PSP_RST_TYPE_PROCESSOR);
     UT_Report(__FILE__, __LINE__,
               UT_PrintfIsInHistory(UT_OSP_MESSAGES[UT_OSP_INSUFF_FREE_SPACE]) &&
@@ -952,7 +952,7 @@ void TestStartupErrorPaths(void)
      * following a failure to remount the RAM volume
      */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_mount), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_mount), OS_ERROR);
     CFE_ES_InitializeFileSystems(CFE_PSP_RST_TYPE_PROCESSOR);
     UT_Report(__FILE__, __LINE__,
               UT_PrintfIsInHistory(UT_OSP_MESSAGES[UT_OSP_INSUFF_FREE_SPACE]) &&
@@ -1022,8 +1022,8 @@ void TestStartupErrorPaths(void)
      * creating a core app
      */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_TaskCreate), OS_ERROR);
-    UT_SetForceFail(UT_KEY(OS_BinSemCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_BinSemCreate), OS_ERROR);
     UT_SetHookFunction(UT_KEY(OS_TaskCreate), ES_UT_SetAppStateHook, NULL);
     CFE_ES_CreateObjects();
     UT_Report(__FILE__, __LINE__,
@@ -1089,8 +1089,8 @@ void TestStartupErrorPaths(void)
      * following a failure to initialize and mount the RAM volume
      */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_initfs), OS_ERROR);
-    UT_SetForceFail(UT_KEY(OS_mount), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_initfs), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_mount), OS_ERROR);
     CFE_ES_InitializeFileSystems(CFE_PSP_RST_TYPE_PROCESSOR);
     UT_Report(__FILE__, __LINE__,
               UT_PrintfIsInHistory(UT_OSP_MESSAGES[UT_OSP_INSUFF_FREE_SPACE]) &&
@@ -1220,7 +1220,7 @@ void TestApps(void)
 
     /* Test starting an application with an open failure */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     CFE_ES_StartApplications(CFE_PSP_RST_TYPE_PROCESSOR,
                              CFE_PLATFORM_ES_NONVOL_STARTUP_FILE);
     UT_Report(__FILE__, __LINE__,
@@ -1267,7 +1267,7 @@ void TestApps(void)
 
     /* Test application loading and creation with a task creation failure */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_TaskCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskCreate), OS_ERROR);
     Return = CFE_ES_AppCreate(&Id,
                               "ut/filename",
                               "EntryPoint",
@@ -1559,7 +1559,7 @@ void TestApps(void)
     UtAppRecPtr->ControlReq.AppControlRequest =
         CFE_ES_RunStatus_SYS_RESTART;
     OS_ModuleLoad(&UtAppRecPtr->ModuleInfo.ModuleId, NULL, NULL, 0);
-    UT_SetForceFail(UT_KEY(OS_TaskCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskCreate), OS_ERROR);
     Id = CFE_ES_AppRecordGetID(UtAppRecPtr);
     CFE_ES_ProcessControlRequest(Id);
     UT_Report(__FILE__, __LINE__,
@@ -1591,7 +1591,7 @@ void TestApps(void)
     UtAppRecPtr->ControlReq.AppControlRequest =
         CFE_ES_RunStatus_SYS_RELOAD;
     OS_ModuleLoad(&UtAppRecPtr->ModuleInfo.ModuleId, NULL, NULL, 0);
-    UT_SetForceFail(UT_KEY(OS_TaskCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskCreate), OS_ERROR);
     Id = CFE_ES_AppRecordGetID(UtAppRecPtr);
     CFE_ES_ProcessControlRequest(Id);
     UT_Report(__FILE__, __LINE__,
@@ -1796,8 +1796,8 @@ void TestApps(void)
     ES_UT_SetupForOSCleanup();
 
     OS_ModuleLoad(&UtAppRecPtr->ModuleInfo.ModuleId, NULL, NULL, 0);
-    UT_SetForceFail(UT_KEY(OS_TaskDelete), OS_ERROR);
-    UT_SetForceFail(UT_KEY(OS_close), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskDelete), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_close), OS_ERROR);
     Id = CFE_ES_AppRecordGetID(UtAppRecPtr);
     UT_Report(__FILE__, __LINE__,
               CFE_ES_CleanUpApp(Id) == CFE_ES_APP_CLEANUP_ERR,
@@ -1926,7 +1926,7 @@ void TestApps(void)
     Id = CFE_ES_TaskRecordGetID(UtTaskRecPtr);
     ES_UT_SetupForOSCleanup();
     UT_SetDeferredRetcode(UT_KEY(OS_TimerGetInfo), 1, OS_ERROR);
-    UT_SetForceFail(UT_KEY(OS_close), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_close), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_ES_CleanupTaskResources(Id) != CFE_SUCCESS,
               "CFE_ES_CleanupTaskResources",
@@ -1939,7 +1939,7 @@ void TestApps(void)
     ES_UT_SetupSingleAppId(CFE_ES_AppType_EXTERNAL, CFE_ES_AppState_RUNNING, NULL, NULL, &UtTaskRecPtr);
     Id = CFE_ES_TaskRecordGetID(UtTaskRecPtr);
     UT_SetDeferredRetcode(UT_KEY(OS_TimerGetInfo), 1, OS_ERROR);
-    UT_SetForceFail(UT_KEY(OS_TaskDelete), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskDelete), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_ES_CleanupTaskResources(Id) == CFE_ES_TASK_DELETE_ERR,
               "CFE_ES_CleanupTaskResources",
@@ -2068,7 +2068,7 @@ void TestApps(void)
     /* switch the main task association (makes it wrong) */
     UtAppRecPtr->MainTaskId = CFE_ES_TaskRecordGetID(UtTaskRecPtr);
 
-    UT_SetForceFail(UT_KEY(OS_TaskDelete), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskDelete), OS_ERROR);
     Id = CFE_ES_AppRecordGetID(UtAppRecPtr);
     UT_Report(__FILE__, __LINE__,
               CFE_ES_CleanUpApp(Id) == CFE_ES_APP_CLEANUP_ERR,
@@ -2290,8 +2290,8 @@ void TestLibs(void)
      * initialization function fails and then must be cleaned up
      */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_remove), OS_ERROR); /* for coverage of error path */
-    UT_SetForceFail(UT_KEY(dummy_function), -555);
+    UT_SetDefaultReturnValue(UT_KEY(OS_remove), OS_ERROR); /* for coverage of error path */
+    UT_SetDefaultReturnValue(UT_KEY(dummy_function), -555);
     Return = CFE_ES_LoadLibrary(&Id,
                                 "/cf/apps/tst_lib.bundle",
                                 "dummy_function",
@@ -2680,7 +2680,7 @@ void TestTask(void)
 
     /* Test task main process loop with an initialization failure */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_TaskRegister), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskRegister), OS_ERROR);
     CFE_ES_TaskMain();
     UT_Report(__FILE__, __LINE__,
               UT_PrintfIsInHistory(UT_OSP_MESSAGES[UT_OSP_APP_INIT]),
@@ -2733,7 +2733,7 @@ void TestTask(void)
 
     /* Test task main process loop with a register app failure */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_TaskRegister), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskRegister), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_ES_TaskInit() == CFE_ES_ERR_APP_REGISTER,
              "CFE_ES_TaskInit",
@@ -2882,7 +2882,7 @@ void TestTask(void)
 
     /* Test app create with an OS task create failure */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_TaskCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskCreate), OS_ERROR);
     UT_CallTaskPipe(CFE_ES_TaskPipe, &CmdBuf.Msg, sizeof(CFE_ES_StartApp_t),
             UT_TPID_CFE_ES_CMD_START_APP_CC);
     UT_Report(__FILE__, __LINE__,
@@ -3196,7 +3196,7 @@ void TestTask(void)
     ES_ResetUnitTest();
     memset(&CmdBuf, 0, sizeof(CmdBuf));
     ES_UT_SetupSingleAppId(CFE_ES_AppType_CORE, CFE_ES_AppState_RUNNING, "CFE_ES", NULL, NULL);
-    UT_SetForceFail(UT_KEY(OS_write), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_write), OS_ERROR);
     UT_CallTaskPipe(CFE_ES_TaskPipe, &CmdBuf.Msg, sizeof(CFE_ES_QueryAll_t),
             UT_TPID_CFE_ES_CMD_QUERY_ALL_CC);
     UT_Report(__FILE__, __LINE__,
@@ -3208,7 +3208,7 @@ void TestTask(void)
     ES_ResetUnitTest();
     memset(&CmdBuf, 0, sizeof(CmdBuf));
     ES_UT_SetupSingleAppId(CFE_ES_AppType_CORE, CFE_ES_AppState_RUNNING, "CFE_ES", NULL, NULL);
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     UT_CallTaskPipe(CFE_ES_TaskPipe, &CmdBuf.Msg, sizeof(CFE_ES_QueryAll_t),
             UT_TPID_CFE_ES_CMD_QUERY_ALL_CC);
     UT_Report(__FILE__, __LINE__,
@@ -3244,7 +3244,7 @@ void TestTask(void)
     ES_ResetUnitTest();
     ES_UT_SetupSingleAppId(CFE_ES_AppType_CORE, CFE_ES_AppState_RUNNING, "UT", NULL, NULL);
     memset(&CmdBuf, 0, sizeof(CmdBuf));
-    UT_SetForceFail(UT_KEY(OS_write), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_write), OS_ERROR);
     UT_CallTaskPipe(CFE_ES_TaskPipe, &CmdBuf.Msg, sizeof(CFE_ES_QueryAllTasks_t),
             UT_TPID_CFE_ES_CMD_QUERY_ALL_TASKS_CC);
     UT_Report(__FILE__, __LINE__,
@@ -3255,7 +3255,7 @@ void TestTask(void)
     /* Test write of all task data to a file with an OS create failure */
     ES_ResetUnitTest();
     memset(&CmdBuf, 0, sizeof(CmdBuf));
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     UT_CallTaskPipe(CFE_ES_TaskPipe, &CmdBuf.Msg, sizeof(CFE_ES_QueryAllTasks_t),
             UT_TPID_CFE_ES_CMD_QUERY_ALL_TASKS_CC);
     UT_Report(__FILE__, __LINE__,
@@ -3322,7 +3322,7 @@ void TestTask(void)
     /* Test writing the system log with an OS create failure */
     ES_ResetUnitTest();
     memset(&CmdBuf, 0, sizeof(CmdBuf));
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     strncpy((char *) CmdBuf.WriteSyslogCmd.Payload.FileName, "",
             sizeof(CmdBuf.WriteSyslogCmd.Payload.FileName));
     UT_CallTaskPipe(CFE_ES_TaskPipe, &CmdBuf.Msg, sizeof(CFE_ES_WriteSyslog_t),
@@ -3335,7 +3335,7 @@ void TestTask(void)
     /* Test writing the system log with an OS write failure */
     ES_ResetUnitTest();
     memset(&CmdBuf, 0, sizeof(CmdBuf));
-    UT_SetForceFail(UT_KEY(OS_write), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_write), OS_ERROR);
     CFE_ES_ResetDataPtr->SystemLogWriteIdx = snprintf(CFE_ES_ResetDataPtr->SystemLog,
             sizeof(CFE_ES_ResetDataPtr->SystemLog),
             "0000-000-00:00:00.00000 Test Message\n");
@@ -3427,7 +3427,7 @@ void TestTask(void)
     /* Test writing the E&R log with an OS create failure */
     ES_ResetUnitTest();
     CFE_ES_TaskData.BackgroundERLogDumpState.IsPending = true;
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     CFE_ES_RunERLogDump(0, &CFE_ES_TaskData.BackgroundERLogDumpState);
     UT_Report(__FILE__, __LINE__,
               UT_EventIsInHistory(CFE_ES_ERLOG2_ERR_EID),
@@ -3437,7 +3437,7 @@ void TestTask(void)
     /* Test writing the E&R log with an OS write failure */
     ES_ResetUnitTest();
     CFE_ES_TaskData.BackgroundERLogDumpState.IsPending = true;
-    UT_SetForceFail(UT_KEY(OS_write), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_write), OS_ERROR);
     CFE_ES_RunERLogDump(0, &CFE_ES_TaskData.BackgroundERLogDumpState);
     UT_Report(__FILE__, __LINE__,
               UT_EventIsInHistory(CFE_ES_FILEWRITE_ERR_EID),
@@ -3456,7 +3456,7 @@ void TestTask(void)
 
     /* Test scan for exceptions in the PSP, should invoke a Processor Reset */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(CFE_PSP_Exception_GetCount), 1);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_PSP_Exception_GetCount), 1);
     CFE_ES_RunExceptionScan(0, NULL);
     UT_Report(__FILE__, __LINE__,
             UT_GetStubCount(UT_KEY(CFE_PSP_Restart)) == 1,
@@ -3466,7 +3466,7 @@ void TestTask(void)
     ES_ResetUnitTest();
     CFE_ES_ResetDataPtr->ResetVars.ProcessorResetCount = 0;
     CFE_ES_ResetDataPtr->ResetVars.MaxProcessorResetCount = 1;
-    UT_SetForceFail(UT_KEY(CFE_PSP_Exception_GetCount), 1);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_PSP_Exception_GetCount), 1);
     CFE_ES_RunExceptionScan(0, NULL);
     /* first time should do a processor restart (limit reached) */
     UT_Report(__FILE__, __LINE__,
@@ -3482,7 +3482,7 @@ void TestTask(void)
 
     /* nominal for app restart - associate exception with a task ID */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(CFE_PSP_Exception_GetCount), 1);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_PSP_Exception_GetCount), 1);
     ES_UT_SetupSingleAppId(CFE_ES_AppType_EXTERNAL, CFE_ES_AppState_RUNNING, NULL, &UtAppRecPtr, &UtTaskRecPtr);
     UT_ContextTask = CFE_ES_ResourceID_ToOSAL(CFE_ES_TaskRecordGetID(UtTaskRecPtr));
     UT_SetDataBuffer(UT_KEY(CFE_PSP_Exception_GetSummary), &UT_ContextTask, sizeof(UT_ContextTask), false);
@@ -3503,7 +3503,7 @@ void TestTask(void)
 
     /* repeat, but for a CORE app, which cannot be restarted */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(CFE_PSP_Exception_GetCount), 1);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_PSP_Exception_GetCount), 1);
     ES_UT_SetupSingleAppId(CFE_ES_AppType_CORE, CFE_ES_AppState_RUNNING, NULL, &UtAppRecPtr, &UtTaskRecPtr);
     UT_ContextTask = CFE_ES_ResourceID_ToOSAL(CFE_ES_TaskRecordGetID(UtTaskRecPtr));
     UT_SetDataBuffer(UT_KEY(CFE_PSP_Exception_GetSummary), &UT_ContextTask, sizeof(UT_ContextTask), false);
@@ -3516,7 +3516,7 @@ void TestTask(void)
               "Scan for exceptions; core app, psp restart");
 
     /* check failure of getting summary data */
-    UT_SetForceFail(UT_KEY(CFE_PSP_Exception_GetSummary), CFE_PSP_NO_EXCEPTION_DATA);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_PSP_Exception_GetSummary), CFE_PSP_NO_EXCEPTION_DATA);
     CFE_ES_RunExceptionScan(0, NULL);
     UT_Report(__FILE__, __LINE__,
             UT_GetStubCount(UT_KEY(CFE_PSP_Restart)) == 2,
@@ -3641,7 +3641,7 @@ void TestTask(void)
     /* Test dumping of the CDS to a file with an OS create failure */
     ES_ResetUnitTest();
     memset(&CmdBuf, 0, sizeof(CmdBuf));
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     UT_CallTaskPipe(CFE_ES_TaskPipe, &CmdBuf.Msg, sizeof(CFE_ES_DumpCDSRegistry_t),
             UT_TPID_CFE_ES_CMD_DUMP_CDS_REGISTRY_CC);
     UT_Report(__FILE__, __LINE__,
@@ -3652,7 +3652,7 @@ void TestTask(void)
     /* Test dumping of the CDS to a file with an OS write failure */
     ES_ResetUnitTest();
     memset(&CmdBuf, 0, sizeof(CmdBuf));
-    UT_SetForceFail(UT_KEY(OS_write), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_write), OS_ERROR);
     ES_UT_SetupSingleCDSRegistry("CFE_ES.CDS_NAME", ES_UT_CDS_BLOCK_SIZE, false, NULL);
     UT_CallTaskPipe(CFE_ES_TaskPipe, &CmdBuf.Msg, sizeof(CFE_ES_DumpCDSRegistry_t),
             UT_TPID_CFE_ES_CMD_DUMP_CDS_REGISTRY_CC);
@@ -4391,7 +4391,7 @@ void TestPerf(void)
     memset(&CFE_ES_TaskData.BackgroundPerfDumpState, 0,
                 sizeof(CFE_ES_TaskData.BackgroundPerfDumpState));
     CFE_ES_TaskData.BackgroundPerfDumpState.PendingState = CFE_ES_PerfDumpState_INIT;
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), -10);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), -10);
     CFE_ES_RunPerfLogDump(1000, &CFE_ES_TaskData.BackgroundPerfDumpState);
     UtAssert_True(CFE_ES_TaskData.BackgroundPerfDumpState.CurrentState == CFE_ES_PerfDumpState_IDLE,
             "CFE_ES_RunPerfLogDump - OS create fail, CFE_ES_TaskData.BackgroundPerfDumpState.CurrentState (%d) == IDLE (%d)",
@@ -4403,7 +4403,7 @@ void TestPerf(void)
     ES_ResetUnitTest();
     memset(&CFE_ES_TaskData.BackgroundPerfDumpState, 0,
             sizeof(CFE_ES_TaskData.BackgroundPerfDumpState));
-    UT_SetForceFail(UT_KEY(OS_write), -10);
+    UT_SetDefaultReturnValue(UT_KEY(OS_write), -10);
     CFE_ES_TaskData.BackgroundPerfDumpState.PendingState = CFE_ES_PerfDumpState_INIT;
     CFE_ES_RunPerfLogDump(1000, &CFE_ES_TaskData.BackgroundPerfDumpState);
     UtAssert_True(CFE_ES_TaskData.BackgroundPerfDumpState.CurrentState == CFE_ES_PerfDumpState_DELAY,
@@ -4745,7 +4745,7 @@ void TestAPI(void)
               "Get task info by ID; NULL buffer");
 
     /* Test getting task information using the task ID - bad task ID  */
-    UT_SetForceFail(UT_KEY(OS_ObjectIdToArrayIndex), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_ObjectIdToArrayIndex), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_ES_GetTaskInfo(&TaskInfo, TaskId) == CFE_ES_ERR_RESOURCEID_NOT_VALID,
               "CFE_ES_GetTaskInfo",
@@ -4806,7 +4806,7 @@ void TestAPI(void)
     /* Test creating a child task with an OS task create failure */
     ES_ResetUnitTest();
     ES_UT_SetupSingleAppId(CFE_ES_AppType_EXTERNAL, CFE_ES_AppState_RUNNING, NULL, NULL, NULL);
-    UT_SetForceFail(UT_KEY(OS_TaskCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskCreate), OS_ERROR);
     Return = CFE_ES_CreateChildTask(&TaskId,
                                     "TaskName",
                                     TestAPI,
@@ -4880,7 +4880,7 @@ void TestAPI(void)
     ES_UT_SetupSingleAppId(CFE_ES_AppType_EXTERNAL, CFE_ES_AppState_RUNNING, NULL, &UtAppRecPtr, NULL);
     ES_UT_SetupChildTaskId(UtAppRecPtr, NULL, &UtTaskRecPtr);
     TestObjId = CFE_ES_ResourceID_ToOSAL(CFE_ES_TaskRecordGetID(UtTaskRecPtr));
-    UT_SetForceFail(UT_KEY(OS_TaskGetId), OS_ObjectIdToInteger(TestObjId)); /* Set context to that of child */
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskGetId), OS_ObjectIdToInteger(TestObjId)); /* Set context to that of child */
     Return = CFE_ES_CreateChildTask(&TaskId,
                                     "TaskName",
                                     TestAPI,
@@ -4918,7 +4918,7 @@ void TestAPI(void)
               "Task ID belongs to a main task");
 
     /* Test deleting a child task with an invalid task ID */
-    UT_SetForceFail(UT_KEY(OS_ObjectIdToArrayIndex), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_ObjectIdToArrayIndex), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_ES_DeleteChildTask(TaskId) == CFE_ES_ERR_RESOURCEID_NOT_VALID,
               "CFE_ES_DeleteChildTask",
@@ -4950,7 +4950,7 @@ void TestAPI(void)
     ES_UT_SetupChildTaskId(UtAppRecPtr, NULL, &UtTaskRecPtr);
     AppId = CFE_ES_AppRecordGetID(UtAppRecPtr); /* the app ID */
     TaskId = CFE_ES_TaskRecordGetID(UtTaskRecPtr); /* the child task ID */
-    UT_SetForceFail(UT_KEY(OS_TaskDelete), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskDelete), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_ES_DeleteChildTask(TaskId) <= 0,
               "CFE_ES_DeleteChildTask",
@@ -4969,7 +4969,7 @@ void TestAPI(void)
     ES_UT_SetupSingleAppId(CFE_ES_AppType_EXTERNAL, CFE_ES_AppState_RUNNING, NULL, &UtAppRecPtr, NULL);
     ES_UT_SetupChildTaskId(UtAppRecPtr, NULL, &UtTaskRecPtr);
     TestObjId = CFE_ES_ResourceID_ToOSAL(CFE_ES_TaskRecordGetID(UtTaskRecPtr));
-    UT_SetForceFail(UT_KEY(OS_TaskGetId), OS_ObjectIdToInteger(TestObjId)); /* Set context to that of child */
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskGetId), OS_ObjectIdToInteger(TestObjId)); /* Set context to that of child */
     CFE_ES_ExitChildTask();
     UT_Report(__FILE__, __LINE__,
               UT_GetStubCount(UT_KEY(OS_TaskExit)) == 1,
@@ -4998,7 +4998,7 @@ void TestAPI(void)
 
     /* Test registering a child task with an OS task register failure */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(OS_TaskRegister), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TaskRegister), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_ES_RegisterChildTask() == CFE_ES_ERR_CHILD_TASK_REGISTER,
               "CFE_ES_RegisterChildTask",
@@ -5658,7 +5658,7 @@ void TestCDS()
 
     /* Test CDS initialization with size not obtainable */
     ES_ResetUnitTest();
-    UT_SetForceFail(UT_KEY(CFE_PSP_GetCDSSize), -1);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_PSP_GetCDSSize), -1);
     UT_Report(__FILE__, __LINE__,
               CFE_ES_CDS_EarlyInit() == OS_ERROR,
               "CFE_ES_CDS_EarlyInit",
@@ -6760,7 +6760,7 @@ void TestBackground(void)
     ES_ResetUnitTest();
     memset(&CFE_ES_TaskData.BackgroundPerfDumpState, 0,
             sizeof(CFE_ES_TaskData.BackgroundPerfDumpState));
-    UT_SetForceFail(UT_KEY(OS_write), -10);
+    UT_SetDefaultReturnValue(UT_KEY(OS_write), -10);
     CFE_ES_TaskData.BackgroundPerfDumpState.CurrentState = CFE_ES_PerfDumpState_INIT;
     UT_SetDeferredRetcode(UT_KEY(OS_BinSemTimedWait), 3, -4);
     CFE_ES_BackgroundTask();
diff --git a/fsw/cfe-core/unit-test/evs_UT.c b/fsw/cfe-core/unit-test/evs_UT.c
index 052fffc1f..cd5871836 100644
--- a/fsw/cfe-core/unit-test/evs_UT.c
+++ b/fsw/cfe-core/unit-test/evs_UT.c
@@ -443,7 +443,7 @@ void Test_Init(void)
 
     /* Test task initialization where getting the application ID fails */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_GetAppID), -1);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_GetAppID), -1);
     CFE_EVS_TaskInit();
     UT_Report(__FILE__, __LINE__,
               UT_SyslogIsInHistory(EVS_SYSLOG_MSGS[10]),
@@ -494,7 +494,7 @@ void Test_IllegalAppID(void)
 
     /* Set test up with illegal application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
 
     /* Test registering an event using an illegal application ID */
     UT_Report(__FILE__, __LINE__,
@@ -504,7 +504,7 @@ void Test_IllegalAppID(void)
 
     /* Test unregistering an event using an illegal application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
     UT_Report(__FILE__, __LINE__,
               CFE_EVS_Unregister() == CFE_EVS_APP_ILLEGAL_APP_ID,
               "CFE_EVS_Unregister",
@@ -512,7 +512,7 @@ void Test_IllegalAppID(void)
 
     /* Test sending an event using an illegal application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
     UT_Report(__FILE__, __LINE__,
               CFE_EVS_SendEvent(0, 0, "NULL") == CFE_EVS_APP_ILLEGAL_APP_ID,
               "CFE_EVS_SendEvent",
@@ -520,7 +520,7 @@ void Test_IllegalAppID(void)
 
     /* Test sending an event using an illegal application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
     UT_Report(__FILE__, __LINE__,
               EVS_SendEvent(0, 0, "NULL") == CFE_SUCCESS,
               "EVS_SendEvent",
@@ -528,7 +528,7 @@ void Test_IllegalAppID(void)
 
     /* Test sending a timed event using an illegal application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
     UT_Report(__FILE__, __LINE__,
               CFE_EVS_SendTimedEvent(time,
                                      0,
@@ -539,7 +539,7 @@ void Test_IllegalAppID(void)
 
     /* Test sending an event with app ID using an illegal application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
     UT_Report(__FILE__, __LINE__,
               CFE_EVS_SendEventWithAppID(0,
                                          0,
@@ -550,7 +550,7 @@ void Test_IllegalAppID(void)
 
     /* Test resetting a filter using an illegal application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
     UT_Report(__FILE__, __LINE__,
               CFE_EVS_ResetFilter(0) == CFE_EVS_APP_ILLEGAL_APP_ID,
               "CFE_EVS_ResetFilter",
@@ -558,7 +558,7 @@ void Test_IllegalAppID(void)
 
     /* Test resetting all filters using an illegal application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
     UT_Report(__FILE__, __LINE__,
               CFE_EVS_ResetAllFilters() == CFE_EVS_APP_ILLEGAL_APP_ID,
               "CFE_EVS_ResetAllFilters",
@@ -566,7 +566,7 @@ void Test_IllegalAppID(void)
 
     /* Test application cleanup using an illegal application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_AppID_ToIndex), CFE_ES_ERR_RESOURCEID_NOT_VALID);
     UT_Report(__FILE__, __LINE__,
               CFE_EVS_CleanUpApp(CFE_ES_RESOURCEID_UNDEFINED) ==
                   CFE_EVS_APP_ILLEGAL_APP_ID,
@@ -694,7 +694,7 @@ void Test_FilterRegistration(void)
 
     /* Test filter unregistration with failed ES_putPool */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_PutPoolBuf), -1);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_PutPoolBuf), -1);
     UT_SetDeferredRetcode(UT_KEY(CFE_ES_GetAppID), 1, -1);
     UT_Report(__FILE__, __LINE__,
               CFE_EVS_Unregister() < 0, "CFE_EVS_Unregister",
@@ -1356,7 +1356,7 @@ void Test_Logging(void)
     /* Test writing a log entry with a create failure */
     UT_InitData();
     UT_SetDeferredRetcode(UT_KEY(OS_MutSemCreate), 1, OS_SUCCESS);
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_EVS_WriteLogDataFileCmd(&CmdBuf.logfilecmd) != CFE_SUCCESS,
               "CFE_EVS_WriteLogDataFileCmd",
@@ -1374,7 +1374,7 @@ void Test_Logging(void)
     /* Test writing a log entry with a write failure */
     UT_InitData();
     UT_SetDeferredRetcode(UT_KEY(OS_MutSemCreate), 1, OS_SUCCESS);
-    UT_SetForceFail(UT_KEY(OS_write), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_write), OS_ERROR);
     CFE_EVS_GlobalData.EVS_LogPtr->LogCount = CFE_PLATFORM_EVS_LOG_MAX;
     UT_Report(__FILE__, __LINE__,
               CFE_EVS_WriteLogDataFileCmd(&CmdBuf.logfilecmd) != CFE_SUCCESS,
@@ -1452,7 +1452,7 @@ void Test_WriteApp(void)
     UT_InitData();
     strncpy((char *) CmdBuf.AppDataCmd.Payload.AppDataFilename, "ut_cfe_evs",
             sizeof(CmdBuf.AppDataCmd.Payload.AppDataFilename));
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     UT_EVS_DoDispatchCheckEvents(&CmdBuf.AppDataCmd, sizeof(CmdBuf.AppDataCmd),
                UT_TPID_CFE_EVS_CMD_WRITE_APP_DATA_FILE_CC,
                &UT_EVS_EventBuf);
@@ -1463,8 +1463,8 @@ void Test_WriteApp(void)
 
     /* Test writing application data with a write/close failure */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(OS_write), OS_ERROR);
-    UT_SetForceFail(UT_KEY(OS_close), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_write), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_close), OS_ERROR);
     UT_EVS_DoDispatchCheckEvents(&CmdBuf.AppDataCmd, sizeof(CmdBuf.AppDataCmd),
                UT_TPID_CFE_EVS_CMD_WRITE_APP_DATA_FILE_CC,
                &UT_EVS_EventBuf);
@@ -1489,7 +1489,7 @@ void Test_WriteApp(void)
     UT_InitData();
     strncpy((char *) CmdBuf.AppDataCmd.Payload.AppDataFilename, "AppDataFileName",
             sizeof(CmdBuf.AppDataCmd.Payload.AppDataFilename));
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     UT_EVS_DoDispatchCheckEvents(&CmdBuf.AppDataCmd, sizeof(CmdBuf.AppDataCmd),
                UT_TPID_CFE_EVS_CMD_WRITE_APP_DATA_FILE_CC,
                &UT_EVS_EventBuf);
@@ -1541,7 +1541,7 @@ void Test_BadAppCmd(void)
             sizeof(appcmdcmd.Payload.AppName));
 
     /* Test disabling application event types with an unknown application ID */
-    UT_SetForceFail(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
     UT_EVS_DoDispatchCheckEvents(&appbitcmd, sizeof(appbitcmd),
                UT_TPID_CFE_EVS_CMD_DISABLE_APP_EVENT_TYPE_CC,
                &UT_EVS_EventBuf);
@@ -1552,7 +1552,7 @@ void Test_BadAppCmd(void)
 
     /* Test enabling application event types with an unknown application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
     UT_EVS_DoDispatchCheckEvents(&appbitcmd, sizeof(appbitcmd),
                UT_TPID_CFE_EVS_CMD_ENABLE_APP_EVENT_TYPE_CC,
                &UT_EVS_EventBuf);
@@ -1563,7 +1563,7 @@ void Test_BadAppCmd(void)
 
     /* Test disabling application events with an unknown application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
     UT_EVS_DoDispatchCheckEvents(&appnamecmd, sizeof(appnamecmd),
                UT_TPID_CFE_EVS_CMD_DISABLE_APP_EVENTS_CC,
                &UT_EVS_EventBuf);
@@ -1574,7 +1574,7 @@ void Test_BadAppCmd(void)
 
     /* Test enabling application events with an unknown application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
     UT_EVS_DoDispatchCheckEvents(&appnamecmd, sizeof(appnamecmd),
                UT_TPID_CFE_EVS_CMD_ENABLE_APP_EVENTS_CC,
                &UT_EVS_EventBuf);
@@ -1587,7 +1587,7 @@ void Test_BadAppCmd(void)
      * application ID
      */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
     UT_EVS_DoDispatchCheckEvents(&appnamecmd, sizeof(appnamecmd),
                UT_TPID_CFE_EVS_CMD_RESET_APP_COUNTER_CC,
                &UT_EVS_EventBuf);
@@ -1598,7 +1598,7 @@ void Test_BadAppCmd(void)
 
     /* Test modifying event filters with an unknown application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
     UT_EVS_DoDispatchCheckEvents(&appmaskcmd, sizeof(appmaskcmd),
                UT_TPID_CFE_EVS_CMD_ADD_EVENT_FILTER_CC,
                &UT_EVS_EventBuf);
@@ -1610,7 +1610,7 @@ void Test_BadAppCmd(void)
 
     /* Test deleting event filters with an unknown application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
     UT_EVS_DoDispatchCheckEvents(&appcmdcmd, sizeof(appcmdcmd),
                UT_TPID_CFE_EVS_CMD_DELETE_EVENT_FILTER_CC,
                &UT_EVS_EventBuf);
@@ -1622,7 +1622,7 @@ void Test_BadAppCmd(void)
 
     /* Test setting the event filter mask with an unknown application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
     UT_EVS_DoDispatchCheckEvents(&appmaskcmd, sizeof(appmaskcmd),
                UT_TPID_CFE_EVS_CMD_SET_FILTER_CC,
                &UT_EVS_EventBuf);
@@ -1634,7 +1634,7 @@ void Test_BadAppCmd(void)
 
     /* Test resetting the filter with an unknown application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
     UT_EVS_DoDispatchCheckEvents(&appcmdcmd, sizeof(appcmdcmd),
                UT_TPID_CFE_EVS_CMD_RESET_FILTER_CC,
                &UT_EVS_EventBuf);
@@ -1645,7 +1645,7 @@ void Test_BadAppCmd(void)
 
     /* Test resetting all filters with an unknown application ID */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_GetAppIDByName), CFE_ES_ERR_NAME_NOT_FOUND);
     UT_EVS_DoDispatchCheckEvents(&appnamecmd, sizeof(appnamecmd),
                UT_TPID_CFE_EVS_CMD_RESET_ALL_FILTERS_CC,
                &UT_EVS_EventBuf);
diff --git a/fsw/cfe-core/unit-test/fs_UT.c b/fsw/cfe-core/unit-test/fs_UT.c
index dabd2c3e5..a1b6f5c48 100644
--- a/fsw/cfe-core/unit-test/fs_UT.c
+++ b/fsw/cfe-core/unit-test/fs_UT.c
@@ -95,7 +95,7 @@ void Test_CFE_FS_ReadHeader(void)
 
     /* Test reading the header with a lseek failure */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(OS_lseek), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_lseek), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_FS_ReadHeader(&Hdr, FileDes) == OS_ERROR,
               "CFE_FS_ReadHeader",
@@ -104,7 +104,7 @@ void Test_CFE_FS_ReadHeader(void)
     /* Test successfully reading the header */
     UT_InitData();
     UT_SetDeferredRetcode(UT_KEY(OS_lseek), 1, OS_SUCCESS);
-    UT_SetForceFail(UT_KEY(OS_read), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_read), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_FS_ReadHeader(&Hdr, FileDes) != sizeof(CFE_FS_Header_t),
               "CFE_FS_ReadHeader",
@@ -123,7 +123,7 @@ void Test_CFE_FS_WriteHeader(void)
 
     /* Test writing the header with a lseek failure */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(OS_lseek), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_lseek), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_FS_WriteHeader(FileDes, &Hdr) == OS_ERROR,
               "CFE_FS_WriteHeader",
@@ -151,7 +151,7 @@ void Test_CFE_FS_SetTimestamp(void)
 
     /* Test setting the time stamp with a lseek failure */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(OS_lseek), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_lseek), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_FS_SetTimestamp(FileDes, NewTimestamp) == OS_ERROR,
               "CFE_FS_SetTimestamp",
@@ -159,7 +159,7 @@ void Test_CFE_FS_SetTimestamp(void)
 
     /* Test setting the time stamp with a seconds write failure */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(OS_write), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_write), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_FS_SetTimestamp(FileDes, NewTimestamp) != OS_SUCCESS,
               "CFE_FS_SetTimestamp",
@@ -313,7 +313,7 @@ void Test_CFE_FS_Private(void)
 
     /* Test FS initialization with a mutex creation failure */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(OS_MutSemCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_MutSemCreate), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_FS_EarlyInit() == -1,
               "CFE_FS_EarlyInit",
diff --git a/fsw/cfe-core/unit-test/sb_UT.c b/fsw/cfe-core/unit-test/sb_UT.c
index 369ef3233..507fd2d65 100644
--- a/fsw/cfe-core/unit-test/sb_UT.c
+++ b/fsw/cfe-core/unit-test/sb_UT.c
@@ -566,7 +566,7 @@ void Test_SB_Cmds_RoutingInfoCreateFail(void)
     CFE_SB.CmdPipePktPtr = (CFE_SB_MsgPtr_t) &WriteFileCmd;
 
     /* Make function CFE_SB_SendRtgInfo return CFE_SB_FILE_IO_ERR */
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
 
     CFE_SB_ProcessCmdPipePkt();
 
@@ -686,7 +686,7 @@ void Test_SB_Cmds_PipeInfoSpec(void)
 */
 void Test_SB_Cmds_PipeInfoCreateFail(void)
 {
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     ASSERT_EQ(CFE_SB_SendPipeInfo("PipeTstFile"), CFE_SB_FILE_IO_ERR);
 
     EVTCNT(1);
@@ -821,7 +821,7 @@ void Test_SB_Cmds_MapInfoSpec(void)
 */
 void Test_SB_Cmds_MapInfoCreateFail(void)
 {
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     ASSERT_EQ(CFE_SB_SendMapInfo("MapTstFile"), CFE_SB_FILE_IO_ERR);
 
     EVTCNT(1);
diff --git a/fsw/cfe-core/unit-test/tbl_UT.c b/fsw/cfe-core/unit-test/tbl_UT.c
index e395262f4..a3b35c43b 100644
--- a/fsw/cfe-core/unit-test/tbl_UT.c
+++ b/fsw/cfe-core/unit-test/tbl_UT.c
@@ -737,7 +737,7 @@ void Test_CFE_TBL_DumpToFile(void)
 
     /* Test with an error creating the dump file */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_TBL_DumpToFile("filename" ,"tablename" ,"dumpaddress",
                                  TblSizeInBytes) == CFE_TBL_INC_ERR_CTR,
@@ -1140,7 +1140,7 @@ void Test_CFE_TBL_DumpRegCmd(void)
     UT_InitData();
     strncpy((char *)DumpRegCmd.Payload.DumpFilename, "",
             sizeof(DumpRegCmd.Payload.DumpFilename));
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_TBL_DumpRegistryCmd(&DumpRegCmd) ==
                 CFE_TBL_INC_ERR_CTR,
@@ -1410,7 +1410,7 @@ void Test_CFE_TBL_LoadCmd(void)
     UT_InitData();
     strncpy((char *)LoadCmd.Payload.LoadFilename, "LoadFileName",
             sizeof(LoadCmd.Payload.LoadFilename));
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_TBL_LoadCmd(&LoadCmd) ==
                 CFE_TBL_INC_ERR_CTR,
@@ -1726,7 +1726,7 @@ void Test_CFE_TBL_HousekeepingCmd(void)
     UT_InitData();
     CFE_TBL_TaskData.DumpControlBlocks[0].State = CFE_TBL_DUMP_PERFORMED;
     CFE_TBL_TaskData.HkTlmTblRegIndex = CFE_TBL_NOT_FOUND + 1;
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_TBL_HousekeepingCmd(NULL) == CFE_TBL_DONT_INC_CTR,
               "CFE_TBL_HousekeepingCmd",
@@ -1736,7 +1736,7 @@ void Test_CFE_TBL_HousekeepingCmd(void)
     UT_InitData();
     CFE_TBL_TaskData.HkTlmTblRegIndex = CFE_TBL_NOT_FOUND;
     CFE_TBL_TaskData.DumpControlBlocks[0].State = CFE_TBL_DUMP_PERFORMED;
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     UT_Report(__FILE__, __LINE__,
               CFE_TBL_HousekeepingCmd(NULL) == CFE_TBL_DONT_INC_CTR,
               "CFE_TBL_HousekeepingCmd",
@@ -4212,7 +4212,7 @@ void Test_CFE_TBL_Internal(void)
 
     UT_SetReadBuffer(&TblFileHeader, sizeof(TblFileHeader));
     UT_SetReadHeader(&StdFileHeader, sizeof(StdFileHeader));
-    UT_SetForceFail(UT_KEY(OS_OpenCreate), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_OpenCreate), OS_ERROR);
     RtnCode = CFE_TBL_LoadFromFile("UT", WorkingBufferPtr, RegRecPtr, Filename);
     EventsCorrect = (UT_EventIsInHistory(CFE_TBL_FILE_ACCESS_ERR_EID) == true &&
         UT_GetNumEventsSent() == 1);
@@ -4810,7 +4810,7 @@ void Test_CFE_TBL_Internal(void)
     /* Test successful application cleanup */
     UT_InitData();
     UT_SetAppID(UT_TBL_APPID_1);
-    UT_SetForceFail(UT_KEY(CFE_ES_PutPoolBuf), -1);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_PutPoolBuf), -1);
     AccessDescPtr = &CFE_TBL_TaskData.Handles[App1TblHandle1];
     RegRecPtr = &CFE_TBL_TaskData.Registry[AccessDescPtr->RegIndex];
     CFE_TBL_TaskData.DumpControlBlocks[3].State = CFE_TBL_DUMP_PENDING;
@@ -4981,7 +4981,7 @@ void Test_CFE_TBL_Internal(void)
      */
     UT_InitData();
     UT_SetAppID(UT_TBL_APPID_1);
-    UT_SetForceFail(UT_KEY(CFE_ES_PutPoolBuf), -1);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_ES_PutPoolBuf), -1);
     CFE_TBL_TaskData.Handles[0].AppId = UT_TBL_APPID_1;
     AccessDescPtr = &CFE_TBL_TaskData.Handles[App1TblHandle2];
     RegRecPtr = &CFE_TBL_TaskData.Registry[AccessDescPtr->RegIndex];
diff --git a/fsw/cfe-core/unit-test/time_UT.c b/fsw/cfe-core/unit-test/time_UT.c
index bcb421230..f3e09c649 100644
--- a/fsw/cfe-core/unit-test/time_UT.c
+++ b/fsw/cfe-core/unit-test/time_UT.c
@@ -470,7 +470,7 @@ void Test_Init(void)
 
     /* Test response to a failure to get the ID by name */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(OS_TimeBaseGetIdByName), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TimeBaseGetIdByName), OS_ERROR);
     CFE_TIME_TaskInit();
     UT_Report(__FILE__, __LINE__,
               UT_GetStubCount(UT_KEY(CFE_ES_WriteToSysLog)) == 0,
@@ -482,7 +482,7 @@ void Test_Init(void)
      * error.  This allows the overall system to continue without the 1Hz
      */
     UT_InitData();
-    UT_SetForceFail(UT_KEY(OS_TimerAdd), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TimerAdd), OS_ERROR);
     CFE_TIME_TaskInit();
     UT_Report(__FILE__, __LINE__,
               UT_GetStubCount(UT_KEY(CFE_ES_WriteToSysLog)) == 1 &&
@@ -491,7 +491,7 @@ void Test_Init(void)
               "1Hz OS_TimerAdd failure");
 
     UT_InitData();
-    UT_SetForceFail(UT_KEY(OS_TimerSet), OS_ERROR);
+    UT_SetDefaultReturnValue(UT_KEY(OS_TimerSet), OS_ERROR);
     CFE_TIME_TaskInit();
     UT_Report(__FILE__, __LINE__,
               UT_GetStubCount(UT_KEY(CFE_ES_WriteToSysLog)) == 1 && UT_SyslogIsInHistory((TIME_SYSLOG_MSGS[4])),
diff --git a/fsw/cfe-core/unit-test/ut_support.c b/fsw/cfe-core/unit-test/ut_support.c
index b3de436ee..e211ad50b 100644
--- a/fsw/cfe-core/unit-test/ut_support.c
+++ b/fsw/cfe-core/unit-test/ut_support.c
@@ -281,7 +281,7 @@ void UT_SetStatusBSPResetArea(int32 status, uint32 Signature, uint32 ClockSignal
     UT_CFE_ES_ResetData.ResetData.TimeResetVars.ClockSignal = ClockSignal;
     if (status != 0)
     {
-        UT_SetForceFail(UT_KEY(CFE_PSP_GetResetArea), status);
+        UT_SetDefaultReturnValue(UT_KEY(CFE_PSP_GetResetArea), status);
     }
     else
     {
@@ -310,7 +310,7 @@ void UT_SetReadHeader(void *Hdr, int NumBytes)
 */
 void UT_SetDummyFuncRtn(int Return)
 {
-    UT_SetForceFail(UT_KEY(dummy_function), Return);
+    UT_SetDefaultReturnValue(UT_KEY(dummy_function), Return);
 }
 
 /*
diff --git a/modules/sbr/unit-test-coverage/test_cfe_sbr_map_direct.c b/modules/sbr/unit-test-coverage/test_cfe_sbr_map_direct.c
index 770553027..c78c41e2a 100644
--- a/modules/sbr/unit-test-coverage/test_cfe_sbr_map_direct.c
+++ b/modules/sbr/unit-test-coverage/test_cfe_sbr_map_direct.c
@@ -48,7 +48,7 @@ void Test_SBR_Map_Direct(void)
     CFE_SBR_Init_Map();
 
     /* Force valid msgid responses */
-    UT_SetForceFail(UT_KEY(CFE_SB_IsValidMsgId), true);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_SB_IsValidMsgId), true);
 
     UtPrintf("Check that all entries are set invalid");
     count = 0;
diff --git a/modules/sbr/unit-test-coverage/test_cfe_sbr_map_hash.c b/modules/sbr/unit-test-coverage/test_cfe_sbr_map_hash.c
index df78f55c6..1ba6c0db2 100644
--- a/modules/sbr/unit-test-coverage/test_cfe_sbr_map_hash.c
+++ b/modules/sbr/unit-test-coverage/test_cfe_sbr_map_hash.c
@@ -67,7 +67,7 @@ void Test_SBR_Map_Hash(void)
     CFE_SBR_Init();
 
     /* Force valid msgid responses */
-    UT_SetForceFail(UT_KEY(CFE_SB_IsValidMsgId), true);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_SB_IsValidMsgId), true);
 
     UtPrintf("Check that all entries are set invalid");
     count = 0;
diff --git a/modules/sbr/unit-test-coverage/test_cfe_sbr_route_unsorted.c b/modules/sbr/unit-test-coverage/test_cfe_sbr_route_unsorted.c
index ac44c2ec7..2c202d6e0 100644
--- a/modules/sbr/unit-test-coverage/test_cfe_sbr_route_unsorted.c
+++ b/modules/sbr/unit-test-coverage/test_cfe_sbr_route_unsorted.c
@@ -60,7 +60,7 @@ void Test_SBR_Route_Unsort_General(void)
      * Note from here on msgids must be in the valid range since validation is forced true
      * and if the underlying map implentation is direct it needs to be a valid array index
      */
-    UT_SetForceFail(UT_KEY(CFE_SB_IsValidMsgId), true);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_SB_IsValidMsgId), true);
 
     UtPrintf("Callback test with no routes");
     count = 0;
@@ -137,7 +137,7 @@ void Test_SBR_Route_Unsort_GetSet(void)
      * Note from here on msgids must be in the valid range since validation is forced true
      * and if the underlying map implentation is direct it needs to be a valid array index
      */
-    UT_SetForceFail(UT_KEY(CFE_SB_IsValidMsgId), true);
+    UT_SetDefaultReturnValue(UT_KEY(CFE_SB_IsValidMsgId), true);
 
     UtPrintf("Initialize map and route");
     CFE_SBR_Init();