diff --git a/yang-models/_3gpp-common-fm.yang b/yang-models/_3gpp-common-fm.yang
index b067ace3f9eee9798d228269ed4324fb6b19717c..482dabdf5a23b3afdfd795bbdcd12b079d435cde 100755
--- a/yang-models/_3gpp-common-fm.yang
+++ b/yang-models/_3gpp-common-fm.yang
@@ -16,6 +16,7 @@ module _3gpp-common-fm {
     TTA, TTC). All rights reserved.";
   reference "3GPP TS 28.111";
 
+  revision 2025-08-13 { reference "CR-0053 CR-0054"; }
   revision 2025-05-01 { reference "CR-0042 CR-0043"; }  // common for R18, R19
   revision 2025-03-25 { reference "CR-0025 CR-0026"; } 
   revision 2024-05-12 { 
@@ -104,6 +105,218 @@ module _3gpp-common-fm {
     description "The possible alarm severities";
   }
 
+  typedef probable-causes {
+    type enumeration {
+      enum INDETERMINATE { value 0; }
+      enum ALARM_INDICATION_SIGNAL { value 1; }
+      enum CALL_SETUP_FAILURE { value 2; }
+      enum DEGRADED_SIGNAL { value 3; }
+      enum FAR_END_RECEIVER_FAILURE { value 4; }
+      enum FRAMING_ERROR { value 5; }
+      enum LOSS_OF_FRAME { value 6; }
+      enum LOSS_OF_POINTER { value 7; }
+      enum LOSS_OF_SIGNAL { value 8; }
+      enum PAYLOAD_TYPE_MISMATCH { value 9; }
+      enum REMOTE_ALARM_INTERFACE { value 11; }
+      enum EXCESSIVE_BIT_ERROR_RATE { value 12; }
+      enum PATH_TRACE_MISMATCH { value 13; }
+      enum UNAVAILABLE { value 14; }
+      enum SIGNAL_LABEL_MISMATCH { value 15; }
+      enum LOSS_OF_MULTI_FRAME { value 16; }
+      enum COMMUNICATIONS_RECEIVE_FAILURE { value 17; }
+      enum COMMUNICATIONS_TRANSMIT_FAILURE { value 18; }
+      enum MODULATION_FAILURE { value 19; }
+      enum DEMODULATION_FAILURE { value 20; }
+      enum BACK_PLANE_FAILURE { value 51; }
+      enum DATA_SET_PROBLEM { value 52; }
+      enum EQUIPMENT_IDENTIFIER_DUPLICATION { value 53; }
+      enum EXTERNAL_IF_DEVICE_PROBLEM { value 54; }
+      enum LINE_CARD_PROBLEM { value 55; }
+      enum MULTIPLEXER_PROBLEM { value 56; }
+      enum NE_IDENTIFIER_DUPLICATION { value 57; }
+      enum POWER_PROBLEM { value 58; }
+      enum PROCESSOR_PROBLEM { value 59; }
+      enum PROTECTION_PATH_FAILURE { value 60; }
+      enum RECEIVER_FAILURE { value 61; }
+      enum REPLACEABLE_UNIT_MISSING { value 62; }
+      enum REPLACEABLE_UNIT_TYPE_MISMATCH { value 63; }
+      enum SYNCHRONIZATION_SOURCE_MISMATCH { value 64; }
+      enum TERMINAL_PROBLEM { value 65; }
+      enum TIMING_PROBLEM { value 66; }
+      enum TRANSMITTER_FAILURE { value 67; }
+      enum TRUNK_CARD_PROBLEM { value 68; }
+      enum REPLACEABLE_UNIT_PROBLEM { value 69; }
+      enum REAL_TIME_CLOCK_FAILURE { value 70; }
+      enum PROTECTION_MECHANISM_FAILURE { value 81; }
+      enum PROTECTING_RESOURCE_FAILURE { value 82; }
+      enum AIR_COMPRESSOR_FAILURE { value 101; }
+      enum AIR_CONDITIONING_FAILURE { value 102; }
+      enum AIR_DRYER_FAILURE { value 103; }
+      enum BATTERY_DISCHARGING { value 104; }
+      enum BATTERY_FAILURE { value 105; }
+      enum COMMERCIAL_POWER_FAILURE { value 106; }
+      enum COOLING_FAN_FAILURE { value 107; }
+      enum ENGINE_FAILURE { value 108; }
+      enum FIRE_DETECTOR_FAILURE { value 109; }
+      enum FUSE_FAILURE { value 110; }
+      enum GENERATOR_FAILURE { value 111; }
+      enum LOW_BATTERY_THRESHOLD { value 112; }
+      enum PUMP_FAILURE { value 113; }
+      enum RECTIFIER_FAILURE { value 114; }
+      enum RECTIFIER_HIGH_VOLTAGE { value 115; }
+      enum RECTIFIER_LOW_F_VOLTAGE { value 116; }
+      enum VENTILATION_SYSTEM_FAILURE { value 117; }
+      enum ENCLOSURE_DOOR_OPEN { value 118; }
+      enum EXPLOSIVE_GAS { value 119; }
+      enum FIRE { value 120; }
+      enum FLOOD { value 121; }
+      enum HIGH_HUMIDITY { value 122; }
+      enum HIGH_TEMPERATURE { value 123; }
+      enum HIGH_WIND { value 124; }
+      enum ICE_BUILD_UP { value 125; }
+      enum INTRUSION_DETECTION { value 126; }
+      enum LOW_FUEL { value 127; }
+      enum LOW_HUMIDITY { value 128; }
+      enum LOW_CABLE_PRESSURE { value 129; }
+      enum LOW_TEMPERATURE { value 130; }
+      enum LOW_WATER { value 131; }
+      enum SMOKE { value 132; }
+      enum TOXIC_GAS { value 133; }
+      enum EXTERNAL_POINT_FAILURE { value 136; }
+      enum STORAGE_CAPACITY_PROBLEM { value 151; }
+      enum MEMORY_MISMATCH { value 152; }
+      enum CORRUPT_DATA { value 153; }
+      enum OUT_OF_CPU_CYCLES { value 154; }
+      enum SOFTWARE_ENVIRONMENT_PROBLEM { value 155; }
+      enum SOFTWARE_DOWNLOAD_FAILURE { value 156; }
+      enum LOSS_OF_REAL_TIME { value 157; }
+      enum REINITIALIZED { value 158; }
+      enum EXCESSIVE_ERROR_RATE { value 203; }
+      enum ADAPTER_ERROR { value 301; }
+      enum APPLICATION_SUBSYSTEM_FAILURE { value 302; }
+      enum BANDWIDTH_REDUCED { value 303; }
+      enum COMMUNICATIONS_PROTOCOL_ERROR { value 305; }
+      enum COMMUNICATIONS_SUBSYSTEM_FAILURE { value 306; }
+      enum CONFIGURATION_OR_CUSTOMIZATION_ERROR { value 307; }
+      enum CONGESTION { value 308; }
+      enum CPU_CYCLES_LIMIT_EXCEEDED { value 310; }
+      enum DATA_SET_OR_MODEM_ERROR { value 311; }
+      enum DTE_DCE_INTERFACE_ERROR { value 313; }
+      enum EQUIPMENT_MALFUNCTION { value 315; }
+      enum EXCESSIVE_VIBRATION { value 316; }
+      enum FILE_ERROR { value 317; }
+      enum HEATING_OR_VENTILATION_OR_COOLING_SYSTEM_PROBLEM { value 321; }
+      enum HUMIDITY_UNACCEPTABLE { value 322; }
+      enum INPUT_OUTPUT_DEVICE_ERROR { value 323; }
+      enum INPUT_DEVICE_ERROR { value 324; }
+      enum LAN_ERROR { value 325; }
+      enum LEAK_DETECTED { value 326; }
+      enum LOCAL_NODE_TRANSMISSION_ERROR { value 327; }
+      enum MATERIAL_SUPPLY_EXHAUSTED { value 330; }
+      enum OUT_OF_MEMORY { value 332; }
+      enum OUTPUT_DEVICE_ERROR { value 333; }
+      enum PERFORMANCE_DEGRADED { value 334; }
+      enum PRESSURE_UNACCEPTABLE { value 336; }
+      enum QUEUE_SIZE_EXCEEDED { value 339; }
+      enum RECEIVE_FAILURE { value 340; }
+      enum REMOTE_NODE_TRANSMISSION_ERROR { value 342; }
+      enum RESOURCE_AT_OR_NEARING_CAPACITY { value 343; }
+      enum RESPONSE_TIME_EXCESSIVE { value 344; }
+      enum RETRANSMISSION_RATE_EXCESSIVE { value 345; }
+      enum SOFTWARE_ERROR { value 346; }
+      enum SOFTWARE_PROGRAM_ABNORMALLY_TERMINATED { value 347; }
+      enum SOFTWARE_PROGRAM_ERROR { value 348; }
+      enum TEMPERATURE_UNACCEPTABLE { value 350; }
+      enum THRESHOLD_CROSSED { value 351; }
+      enum TOXIC_LEAK_DETECTED { value 353; }
+      enum TRANSMIT_FAILURE { value 354; }
+      enum UNDERLYING_RESOURCE_UNAVAILABLE { value 356; }
+      enum VERSION_MISMATCH { value 357; }
+      enum A_BIS_TO_BTS_INTERFACE_FAILURE { value 501; }
+      enum A_BIS_TO_TRX_INTERFACE_FAILURE { value 502; }
+      enum ANTENNA_PROBLEM { value 503; }
+      enum BATTERY_BREAKDOWN { value 504; }
+      enum BATTERY_CHARGING_FAULT { value 505; }
+      enum CLOCK_SYNCHRONIZATION_PROBLEM { value 506; }
+      enum COMBINER_PROBLEM { value 507; }
+      enum DISK_PROBLEM { value 508; }
+      enum EXCESSIVE_RECEIVER_TEMPERATURE { value 510; }
+      enum EXCESSIVE_TRANSMITTER_OUTPUT_POWER { value 511; }
+      enum EXCESSIVE_TRANSMITTER_TEMPERATURE { value 512; }
+      enum FREQUENCY_HOPPING_DEGRADED { value 513; }
+      enum FREQUENCY_HOPPING_FAILURE { value 514; }
+      enum FREQUENCY_REDEFINITION_FAILED { value 515; }
+      enum LINE_INTERFACE_FAILURE { value 516; }
+      enum LINK_FAILURE { value 517; }
+      enum LOSS_OF_SYNCHRONIZATION { value 518; }
+      enum LOST_REDUNDANCY { value 519; }
+      enum MAINS_BREAKDOWN_WITH_BATTERY_BACKUP { value 520; }
+      enum MAINS_BREAKDOWN_WITHOUT_BATTERY_BACKUP { value 521; }
+      enum POWER_SUPPLY_FAILURE { value 522; }
+      enum RECEIVER_ANTENNA_FAULT { value 523; }
+      enum RECEIVER_MULTICOUPLER_FAILURE { value 525; }
+      enum REDUCED_TRANSMITTER_OUTPUT_POWER { value 526; }
+      enum SIGNAL_QUALITY_EVALUATION_FAULT { value 527; }
+      enum TIMESLOT_HARDWARE_FAILURE { value 528; }
+      enum TRANSCEIVER_PROBLEM { value 529; }
+      enum TRANSCODER_PROBLEM { value 530; }
+      enum TRANSCODER_OR_RATE_ADAPTER_PROBLEM { value 531; }
+      enum TRANSMITTER_ANTENNA_FAILURE { value 532; }
+      enum TRANSMITTER_ANTENNA_NOT_ADJUSTED { value 533; }
+      enum TRANSMITTER_LOW_VOLTAGE_OR_CURRENT { value 535; }
+      enum TRANSMITTER_OFF_FREQUENCY { value 536; }
+      enum DATABASE_INCONSISTENCY { value 537; }
+      enum FILE_SYSTEM_CALL_UNSUCCESSFUL { value 538; }
+      enum INPUT_PARAMETER_OUT_OF_RANGE { value 539; }
+      enum INVALID_PARAMETER { value 540; }
+      enum INVALID_POINTER { value 541; }
+      enum MESSAGE_NOT_EXPECTED { value 542; }
+      enum MESSAGE_NOT_INITIALIZED { value 543; }
+      enum MESSAGE_OUT_OF_SEQUENCE { value 544; }
+      enum SYSTEM_CALL_UNSUCCESSFUL { value 545; }
+      enum TIMEOUT_EXPIRED { value 546; }
+      enum VARIABLE_OUT_OF_RANGE { value 547; }
+      enum WATCH_DOG_TIMER_EXPIRED { value 548; }
+      enum COOLING_SYSTEM_FAILURE { value 549; }
+      enum EXTERNAL_EQUIPMENT_FAILURE { value 550; }
+      enum EXTERNAL_POWER_SUPPLY_FAILURE { value 551; }
+      enum EXTERNAL_TRANSMISSION_DEVICE_FAILURE { value 552; }
+      enum REDUCED_ALARM_REPORTING { value 561; }
+      enum REDUCED_EVENT_REPORTING { value 562; }
+      enum RECUCED_LOGGING_CAPABILITY { value 563; }
+      enum SYSTEM_RESOURCES_OVERLOAD { value 564; }
+      enum BROADCAST_CHANNEL_FAILURE { value 565; }
+      enum CONNECTION_ESTABLISHMENT_ERROR { value 566; }
+      enum INVALID_MESSAGE_RECEIVED { value 567; }
+      enum INVALID_MSU_RECEIVED { value 568; }
+      enum LAPD_LINK_PROTOCOL_FAILURE { value 569; }
+      enum LOCAL_ALARM_INDICATION { value 570; }
+      enum REMOTE_ALARM_INDICATION { value 571; }
+      enum ROUTING_FAILURE { value 572; }
+      enum SS7_PROTOCOL_FAILURE { value 573; }
+      enum TRANSMISSION_ERROR { value 574; }
+      enum AUTHENTICATION_FAILURE { value 701; }
+      enum BREACH_OF_CONFIDENTIALITY { value 702; }
+      enum CABLE_TAMPER { value 703; }
+      enum DELAYED_INFORMATION { value 704; }
+      enum DENIAL_OF_SERVICE { value 705; }
+      enum DUPLICATE_INFORMATION { value 706; }
+      enum INFORMATION_MISSING { value 707; }
+      enum INFORMATION_MODIFICATION_DETECTED { value 708; }
+      enum INFORMATION_OUT_OF_SEQUENCE { value 709; }
+      enum INTRUSION_DETECTED { value 710; }
+      enum KEY_EXPIRED { value 711; }
+      enum NON_REPUDIATION_FAILURE { value 712; }
+      enum OUT_OF_HOURS_ACTIVITY { value 713; }
+      enum OUT_OF_SERVICE { value 714; }
+      enum PROCEDURAL_ERROR { value 715; }
+      enum UNAUTHORISED_ACCESS_ATTEMPT { value 716; }
+      enum UNEXPECTED_INFORMATION { value 717; }
+      enum UNSPECIFIED_REASON { value 718; }
+    }
+    description "Values are from the (informative) Annex B of 3GPP TS 28.111.";
+  }
+
   grouping AlarmCommentGrp {
     leaf commentTime {
       type yang:date-and-time;
@@ -343,6 +556,7 @@ module _3gpp-common-fm {
 
     leaf probableCause {
       type union {
+        type probable-causes;
         type int32;
         type string;
       }
@@ -678,4 +892,4 @@ module _3gpp-common-fm {
     }
   }
 
-}
+}
\ No newline at end of file