JSC 28549, REQUIREMENTS FOR RELIABILITY AND MAINTENANCE (R&M) ANALYSIS AND ASSESSMENT OF SPACE SHUTTLE AND OTHER SPACECRAFT ELEMENTS (06 OCT 2000)
JSC 28549, REQUIREMENTS FOR RELIABILITY AND MAINTENANCE (R&M) ANALYSIS AND ASSESSMENT OF SPACE SHUTTLE AND OTHER SPACECRAFT ELEMENTS (06 OCT 2000)., This document defines the structure and content of an approach for conducting a reliability and maintenance (R&M) analysis and assessment. It's primary purpose is to serve as an instrument for establishing an R&M analysis and assessment agreement between a contractor and the Safety, Reliability, and Quality Assurance (SR&QA) Office of the Johnson Space Center (JSC). It is also a document that presents basic principles of an R&M analysis and assessment that are endorsed by the SR&QA office of JSC. Accordingly then, this document should be considered by anyone performing an R&M analysis and assessment for the SR&QA office at JSC.
It is recognized that one document cannot cover the best analyses and assessments that should be done over a broad spectrum of problems. This document should not be a substitute for good technical leadership. Conversely, however, good technical arguments should be presented for not following the principles of this document. Reliability and maintenance is not a static science and therefore this document is expected to evolve as it becomes apparent that other aspects of R&M analysis and assessment should be covered. Partially in this spirit of evolving into a more authoritative document, several appendices are included. These appendices have evolved from analyses that have been done prior to the writing of this document. While they represent, possibly an incomplete, theory of how to handle certain circumstances of reliability estimation, they do contain concepts that should be further developed and demonstrated through analysis of real systems.
Emphasis has been placed on reliability and maintenance as a process. In particular, R&M in a space program is difference from R&M that is often related to the manufacturing of a large number of items. There it makes sense to cast reliability in terms related to placing items on test and deducing their propensity to fail. In a typical space program, only a few items are produced, and therefore, to deduce the reliability of an item often requires a process of monitoring, estimation, and assessment that takes place during the operation of the item. During this time the item may be repaired or renewed and placed back in operation and so concepts related to repairable or renewable processes should be considered. And, consequently this is the emphasis that is intended in this document.
Finally, it should be noted that reliability is covered in much more detail than is the subjects of maintenance, cost, and schedule. This reflects the emphasis that has been placed on these subjects in past analyses done by the JSC SR&QA office with the possible exception of certain maintenance analyses and assessments that have been done. Once again this may change as this document evolves.