Common use of Operational Availability Clause in Contracts

Operational Availability. The proportion of time a system is either operating, or is capable of operating, when used in a specific manner in a typical maintenance and supply environment. All calendar time when operating in accordance with wartime operational mode summary/mission profile (OMS/MP) is considered. The formula is as follows: Ao = OT + ST OT + ST + TCM + TPM + TALDT = Total Calendar Time Minus Total Downtime Total Calendar Time Where: OT = The operating time during OMS/MP ST = Standby time (not operating, but assumed operable) during OMS/MP TCM = The total corrective maintenance downtime in clock hours during OMS/MP TPM = The total preventive maintenance downtime in clock hours during OMS/MP TALDT = Total administrative and logistics downtime (caused by OMFs) spent waiting for parts, maintenance personnel, or transportation during OMS/MP. (Note that events attributed to downtime may consist of System Aborts, Mission Affecting Failures, Essential Function Failures, and Essential Maintenance Actions and are system specific dependent on that system’s formally defined Failure Definition/Scoring Criteria.) These closed-form equations are valid when a number of specific assumptions hold and when the system matures to the point that a steady-state behavior develops. The assumptions that must be valid include: 1) the time between failures, times to repair, and ALDT are each exponentially distributed and 2) there is no competition for parts and maintenance resources between individual items. The Army OTA recommends modeling and simulation as a means to address the complexities that arise when the assumptions are not applicable. It is ATEC policy that modeling and simulation be used to evaluate Ao as part of the sustainment KPP. Other forms of this equation are substituted depending on the system type (see AMC/TRADOC ▇▇▇ 70-11) such as the inclusion of relocation time.

Operational Availability. The proportion of time a system is either operating, or is capable of operating, when used in a specific manner in a typical maintenance and supply environment. All calendar time when operating in accordance with wartime operational mode summary/mission profile (OMS/MP) is considered. The formula is as follows: Ao = OT + ST OT + ST + TCM + TPM + TALDT = Total Calendar Time Minus minus Total Downtime Total Calendar Time Where: OT = The operating time during OMS/MP ST = Standby time (not operating, but assumed operable) during OMS/MP TCM = The total corrective maintenance downtime in clock hours during OMS/MP TPM = The total preventive maintenance downtime in clock hours during OMS/MP TALDT = Total administrative and logistics downtime (caused by OMFs) spent waiting for parts, maintenance personnel, or transportation during OMS/MP. (Note that events attributed to downtime may consist of System Aborts, Mission Affecting Failures, Essential Function Failures, and Essential Maintenance Actions and are system specific dependent on that system’s formally defined Failure Definition/Scoring Criteria.) These closed-form equations are valid when a number of specific assumptions hold and when the system matures to the point that a steady-state behavior develops. The assumptions that must be valid include: 1) the time between failures, times to repair, and ALDT are each exponentially distributed and 2) there is no competition for parts and maintenance resources between individual items. The Army OTA recommends modeling and simulation as a means to address the complexities that arise when the assumptions are not applicable. It is ATEC policy that modeling and simulation be used to evaluate Ao as part of the sustainment KPP. Other forms of this equation are substituted depending on the system type (see See AMC/TRADOC ▇▇▇ 70-11) such as the inclusion of relocation time.