DEF STAN 00-43 (PART 1/ISSUE 1), DEFENCE STANDARD: RELIABILITY AND MAINTAINABILITY ASSURANCE ACTIVITY - PART 1: IN-SERVICE RELIABILITY DEMONSTRATIONS (29 JAN 1993). The sections in this Part of the Defence Standard describe the purpose, rationale and procedures for in-Service reliability demonstrations (ISRDs). The purpose of an ISRD is to demonstrate compliance with specified reliability requirements of an equipment or system. An ISRD is a final test to provide motivation and incentive to the contractor to ensure that the reliability programme is vigorously pursued. It supplements rather than replaces other activities in the reliability programme. However, an ISRD will not be appropriate for the purchase of every system, platform or equipment. Experience from completed ISRDs guidance for both MOD and industry.