Software reliability evaluation of the X-29A flight control system

Data from flight tests of the X-29A have been studied using the Statistical Modeling and Estimation of Reliability Functions for Software (SMERFS) modeling package. An overview of the X-29 program is presented. The failure reporting process and the testing strategy from which the failure data were collected are presented. The data are then segregated and analyzed with engineering judgment. The results of executing representative models in the SMERFS software package with these data are presented. Comparisons are made between the raw data analysis and the statistical model results. General observations from this analysis are summarized, with a discussion on the need within NASA to incorporate software reliability techniques