Common use of Maintainability Clause in Contracts

Maintainability. The parameters for addressing maintainability are mean corrective maintenance time for operational mission failures (MCMTOMF), maximum corrective maintenance time for operational mission failures (MaxCMTOMF), mean corrective maintenance time for operational mission faults-software (MCMTOMFSW), MRT, BIT, and MR. (1) MCMTOMF is the average elapsed corrective maintenance time needed to repair all operational mission hardware failures. It includes time for maintenance preparation, fault location and isolation, on-board parts procurement, fault correction, adjustment and calibration, as well as follow-up checkout time. It does not include off-board logistic delay time. MCMTOMF = Total Elapsed Time to Correct Operational Mission Failures Total Number of Operational Mission Failures Onboard logistic delay is the logistic delay associated with obtaining the spare part at the unit or organizational level. For aircraft systems, the squadron will be considered the unit level. Therefore; MCMTOMF will be calculated as the mean of the elapsed maintenance time (block A45 of the maintenance action form). (2) MaxCMTOMF is that time below which a specified percentage of corrective maintenance tasks must be completed to restore the system to operation after an OMF; e.g., 90 percent of all corrective maintenance times for operational mission hardware repairs will be less than MaxCMTOMF. This parameter is recommended when the time required to repair and restore the system due to operational urgency is considered an important aspect of the system under test. (3) MCMTOMFSW is the average elapsed time needed to restore a software-intensive system following an operational mission software fault. The system is considered to be restored when a tactical picture that is useful to the tactical action officer/operator is first established. This may include the time to restore all processes, functions, files, and databases to a tactically useful state as well as the time required to physically reboot the system following an operational mission software fault. It does not include the time to obtain spare parts or utilize the expertise of personnel outside the unit or organizational level. For aircraft systems, the unit level will be the squadron. MCMTOMFsw = (4) MRT is the average elapsed time required to reboot a software-intensive system. MRT is addressed as cold start MRT (MRTC) and warm start MRT (MRTW). Both MRTC and MRTW include only the time necessary to physically reboot the system, not the time required for restoration of the tactical picture as in MCMTOMFSW. (5) BIT is addressed using these parameters: Pcd; Xxxx; and probability of a FA. It is recommended that all three equations be used together to ensure a complete picture of BIT performance. (a) Pcd is a measure of BIT's capability to detect failures/faults and is calculated as: Pcd = Number of Failures / Faults Correctly Detected by BIT Number of Actual System Failures / Faults (b) Pcfi is a measure of BIT's capability to isolate the failure/fault to a specified replaceable assembly and is calculated as: (c) FA is the measure of BIT indicating a failure/fault when none has occurred and is calculated as: FA = Number of Incorrect BIT Failure/Fault Indications Total Number of BIT Failure/Fault Indications For system tests with few BIT failure indications, the FA rate may not provide an accurate measure of false alarms. The OTD may also calculate the number of False Alarms per System Operating Hour (FAh).

Maintainability. The parameters for addressing maintainability are mean corrective maintenance time for operational mission failures (MCMTOMF), maximum corrective maintenance time for operational mission failures (MaxCMTOMF), mean corrective maintenance time for operational mission faults-software (MCMTOMFSW), mean reboot time (MRT), built-in test (BIT), and maintenance ratio (MR). (1) MCMTOMF is the average elapsed corrective maintenance time needed to repair all operational mission hardware failures. It includes time for maintenance preparation, fault location and isolation, on-board parts procurement, fault correction, adjustment and calibration, as well as follow-up checkout time. It does not include off-board logistic delay time. MCMTOMF = Total Elapsed Time to Correct Operational Mission Failures Total Number of Operational Mission Failures Onboard On-board logistic delay is the logistic delay associated with obtaining the spare part at the unit or organizational level. For aircraft systems, the squadron unit level will be considered to be the unit levelsquadron. Therefore; MCMTOMF will be calculated as the mean of the elapsed maintenance time (block A45 of the maintenance action form). (2) MaxCMTOMF is that time below which a specified percentage of corrective maintenance mainte- xxxxx tasks must be completed to restore the system to operation after an operational mission failure (OMF); e.g., 90 percent 90% of all corrective maintenance times for operational mission hardware repairs will be less than MaxCMTOMF. This parameter is recommended when the time required to repair and restore the system due to operational urgency is considered an important aspect of the system under test. (3) MCMTOMFSW is the average elapsed time needed to restore a software-intensive system following an operational mission software fault. The system is considered to be restored when a tactical picture that is useful to the tactical action officer/operator is first established. This may include the time to restore all processes, functions, files, and databases to a tactically useful state as well as the time required to physically reboot the system following an operational mission software fault. It does not include the time to obtain spare parts or utilize the expertise of personnel outside the unit or organizational level. For aircraft systems, the unit level will be the squadron. MCMTOMFsw = (4) MRT is the average elapsed time required to reboot a software-intensive system. MRT is addressed as cold start MRT (MRTC) and warm start MRT (MRTW). Both MRTC and MRTW include only the time necessary to physically reboot the system, not the time required for restoration of the tactical picture as in MCMTOMFSW. (5) BIT is addressed using these parameters: probability of correct detection (Pcd); Xxxxprobability of correct fault isolation (Pcfi); and probability of a false alarm (FA). It is recommended that all three equations be used together to ensure a complete picture of BIT performance. (a) Pcd is a measure of BIT's capability to detect failures/faults and is calculated as: Pcd = Number of Failures / Faults Correctly Detected by BIT Number of Actual System Failures / Faults (b) Pcfi is a measure of BIT's capability to isolate the failure/fault to a specified replaceable assembly and is calculated as: (c) FA is the measure of BIT indicating a failure/fault when none has occurred and is calculated as: FA = Number of Incorrect BIT Failure/Fault Indications Total Number of BIT Failure/Fault Indications For system tests with few BIT failure indications, the FA rate may not provide an accurate measure of false alarms. The OTD may also calculate the number of False Flase Alarms per System Operating Hour (FAh).

Maintainability. The parameters for addressing maintainability are mean corrective maintenance time for operational mission failures (MCMTOMF), maximum corrective maintenance time for operational mission failures (MaxCMTOMF), mean corrective maintenance time for operational mission faults-software (MCMTOMFSW), MRT, BIT, and MR. (1) MCMTOMF is the average elapsed corrective maintenance time needed to repair all operational mission hardware failures. It includes time for maintenance preparation, fault location and isolation, on-board parts procurement, fault correction, adjustment and calibration, as well as follow-up checkout time. It does not include off-board logistic delay time. MCMTOMF = Total Elapsed Time to Correct Operational Mission Failures Total Number of Operational Mission Failures Onboard logistic delay is the logistic delay associated with obtaining the spare part at the unit or organizational level. For aircraft systems, the squadron will be considered the unit level. Therefore; MCMTOMF will be calculated as the mean of the elapsed maintenance time (block A45 of the maintenance action form). (2) MaxCMTOMF is that time below which a specified percentage of corrective maintenance tasks must be completed to restore the system to operation after an OMF; e.g., 90 percent of all corrective maintenance times for operational mission hardware repairs will be less than MaxCMTOMF. This parameter is recommended when the time required to repair and restore the system due to operational urgency is considered an important aspect of the system under test. (3) MCMTOMFSW is the average elapsed time needed to restore a software-intensive system following an operational mission software fault. The system is considered to be restored when a tactical picture that is useful to the tactical action officer/operator is first established. This may include the time to restore all processes, functions, files, and databases to a tactically useful state as well as the time required to physically reboot the system following an operational mission software fault. It does not include the time to obtain spare parts or utilize the expertise of personnel outside the unit or organizational level. For aircraft systems, the unit level will be the squadron. MCMTOMFsw = (4) MRT is the average elapsed time required to reboot a software-intensive system. MRT is addressed as cold start MRT (MRTC) and warm start MRT (MRTW). Both MRTC and MRTW include only the time necessary to physically reboot the system, not the time required for restoration of the tactical picture as in MCMTOMFSW.. Total Number of Software Reboots (5) BIT is addressed using these parameters: Pcd; Xxxx; and probability of a False Alarm (FA). It is recommended that all three equations be used together to ensure a complete picture of BIT performance. (a) Pcd is a measure of BIT's capability to detect failures/faults and is calculated as: Pcd = Number of Failures / Failures/ Faults Correctly Detected by BIT Number of Actual System Failures / Failures/ Faults (b) Pcfi is a measure of BIT's capability to isolate the failure/fault to a specified replaceable assembly and is calculated as: (c) FA is the measure of BIT indicating a failure/fault when none has occurred and is calculated as: FA = Number of Incorrect BIT Failure/Fault Indications Total Number of BIT Failure/Fault Indications For system tests with few BIT failure indications, the FA rate may not provide an accurate measure of false alarms. The OTD Operational Test Director may also calculate the number of False Alarms per System Operating Hour (FAh).. Total Number of Operating Hours

Maintainability. The parameters for addressing maintainability are mean corrective maintenance time for operational mission failures (MCMTOMF), maximum corrective maintenance time for operational mission failures (MaxCMTOMF), mean corrective maintenance time for operational mission faults-software (MCMTOMFSW), mean reboot time (MRT), built-in test (BIT), and maintenance ratio (MR). (1) MCMTOMF is the average elapsed corrective maintenance time needed to repair all operational mission hardware failures. It includes time for maintenance preparation, fault location and isolation, on-board parts procurement, fault correction, adjustment and calibration, as well as follow-up checkout time. It does not include off-board logistic delay time. MCMTOMF = Total Elapsed Time to Correct Operational Mission Failures Total Number of Operational Mission Failures Onboard logistic delay is the logistic delay associated with obtaining the spare part at the unit or organizational level. For aircraft systems, the squadron will be considered the unit level. Therefore; MCMTOMF will be calculated as the mean of the elapsed maintenance time (block A45 of the maintenance action form).Failures (2) MaxCMTOMF is that time below which a specified percentage of corrective maintenance mainte- xxxxx tasks must be completed to restore the system to operation after an operational mission failure (OMF); e.g., 90 percent 90% of all corrective maintenance times for operational mission hardware repairs will be less than MaxCMTOMF. This parameter is recommended when the time required to repair and restore the system due to operational urgency is considered an important aspect of the system under test. (3) MCMTOMFSW is the average elapsed time needed to restore a software-intensive system following an operational mission software fault. The system is considered to be restored when a tactical picture that is useful to the tactical action officer/operator is first established. This may include the time to restore all processes, functions, files, and databases to a tactically useful state as well as the time required to physically reboot the system following an operational mission software fault. It does not include the time to obtain spare parts or utilize the expertise of personnel outside the unit or organizational level. For aircraft systems, the unit level will be the squadron. MCMTOMFsw = (4) MRT is the average elapsed time required to reboot a software-intensive system. MRT is addressed as cold start MRT (MRTC) and warm start MRT (MRTW). Both MRTC and MRTW include only the time necessary to physically reboot the system, not the time required for restoration of the tactical picture as in MCMTOMFSW.. Total Number of Software Reboots (5) BIT is addressed using these parameters: probability of correct detection (Pcd); Xxxxprobability of correct fault isolation (Pcfi); and probability of a false alarm (FA). It is recommended that all three equations be used together to ensure a complete picture of BIT performance. (a) Pcd is a measure of BIT's capability to detect failures/faults and is calculated as: Pcd = Number of Failures / Failures/ Faults Correctly Detected by BIT Number of Actual System Failures / FaultsBIT (b) Pcfi is a measure of BIT's capability to isolate the failure/fault failure to a specified replaceable assembly and is calculated as: Pcfi = Number of Failures Correctly Isolated (c) FA is the measure of BIT indicating a failure/fault failure when none has occurred and is calculated as: FA = Number of Incorrect BIT Failure/Fault Failure Indications Total Number of BIT Failure/Fault Failure Indications For system tests with few FAh = Number of Incorrect BIT failure indications, the FA rate may not provide an accurate measure of false alarms. The OTD may also calculate the number of False Alarms per System Operating Hour (FAh).Failure Indications