An Integrated Life Cycle-based Software Reliability Assurance Approach for NASA Projects
Abstract: 2010 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must first be obtained from the IEEE.
Reliability of complex systems is essentially determined by the reliability of the hardware systems, software and human reliability and associated system interactions as applicable. Over the past few decades, many approaches on hardware/human reliability analyses have been implemented on NASA’s missions  to ensure that the hardware systems meet the target reliability requirements. Recently, with the increasing usage of software as a crucial component in NASA’s missions, it has also become necessary to ensure the reliability of such software . It is widely accepted that software reliability (SWR) is the probability that software will not cause the failure of a system for a specified time under specified conditions . However, it is necessary to point out that SWR can not merely be represented as a probability number, although system level reliability quantification requires a quantitative software reliability estimate. Software reliability is also a qualitative concept which refers to a process: software reliability assurance (SWRA). The objective of SWRA is to ensure that software development has appropriate controls on fault detection, removal, prevention, and risk reduction to ensure successful implementation; and to find out ways to maximize system reliability within cost and schedule constraints. Therefore, SWR is only a subset of SWRA.
Keywords: RAMS 2010 Proceedings - Life Cycle Cost - Product Reliability - Software Reliability