Downloaded from https://www.everyspec.com MIL-HDBK-502: A MIL-HDBK-502: A CQUISITION CQUISITION L OGISTICS OGISTICS 6.2.3 Sample Performance Requirements The following areas—availability, compatibility, transportability, interoperability, etc.—are some of those in which requirements should be stated in performance terms. In each category an example of a supportability requirement expressed in performance terms is provided. These examples illustrate only one of many requirements that might be imposed. Availability A measure of the degree to which an item is in an operable and committable state at the start of a mission when the mission is called for at an unknown (random) time.
Examples The item will have an operational availability of .95 measured by the total operating time divided by the sum of the total operation time, total corrective maintenance time, total preventive maintenance time, and the total administrative and logistics down time. The vehicle will have a maintenance ratio (MR) of the total scheduled and unscheduled maintenance man-hours per hour of operation (excluding operator/crew checks and daily operating service) that does not exceed the following values: (1) ORG 0.140; (2) DS 0.043; (3) Total 0.183.
Operational Sustainability The capability of an item or system, and its inherent support structure, to perform its intended missions over a sustained period of time. Example (Requirement) The portable control station will be capable of completing a sustained 4-day operation using only onboard equipment and spares without resupply or support from personnel other than the operators. (Verification) The operational test of the system will be used to verify the requirement is met. The test will consist of 2 systems performing 4 each of Scenario A, as identified in the ORD, and 2 each of Scenario B (surge), as identified in the ORD.
Nine of the 12 scenarios must be fully executed without outside resupply/assisted maintenance. Additionally, at least one surge scenario must be completed without outside resupply/assisted maintenance. 6-8