Organizational Structure Impacts Flight Software Cost Risk

The Jet Propulsion Laboratory (JPL) has a long record of successful deep-space missions from Explorer to Voyager, to Mars Pathfinder, to Galileo to Mars Odyssey, to name but a few. Our experience and success, as with the rest of the aerospace industry, is built on our hardware and system-level expertise. Throughout the 1990s, software came to play an increasingly more significant role in spacecraft integration, risk, and overall workforce at JPL as well as at other aerospace organizations. During the late 1990s, the importance of software was magnified when a number of JPL-managed missions experienced significant flight software cost growth. In addition, several missions exhibited software-related schedule slips impacting or threatening to impact the planned launch dates. These slips occurred on both in-house and contracted software development projects. In response, JPL funded a 1999 study to identify the systemic causes of reported flight software cost growth and to develop a set of recommendations to reduce the flight software-development cost risk. The results of the 1999 study were reported in two articles. The first article identified the root causes of the observed flight software cost growth (Hihn and Habib-agahi, 2000a), and the second described a set of proposed strategies and policies to reduce software cost growth on future missions (Hihn and Habib-agahi, 2000b). A major recommendation of these studies was to change the organizational structure of a software project so that the software manager had more responsibilities and accessible reporting relationships. In 2003 to 2004, a follow-up study was conducted on seven flight projects that launched from summer of 2001 to 2005, to see if anything had changed since 1999 and if any of the initial report’s recommendations had been implemented. The preliminary results of the follow-up study (Hihn et al., 2003) indicated that having a software management team in place well before system preliminary design review (PDR) with budget and design authority did significantly reduce the likelihood of post-PDR software cost growth. The result that organizational and management structure of software projects has a significant impact on software cost growth, is consistent with Capers Jones’ conclusion that, “deficiencies of the project management function is a fundamental root cause of software disaster” (Jones 1996, 152). The importance of communication was also documented in (Hihn et al. 1990), which showed that the impact of software volatility on software development productivity was greatly mitigated when there was extensive communication within a software development team and between the team and customers. This article summarizes the final results of the follow-up study updating the estimated software effort growth for those projects that were still under development and includes an evaluation of the software management roles versus observed cost risk for the missions included in the original study, which expands the data set to 15 missions. In the final version of the 2004 study, the estimated cost growth for those missions not launched were updated and the role statements for the software managers were evaluated and included for the missions from the 1999 study to expand the data set and better document any changes in their roles between the studies. The expanded data set made it possible to expand the analysis to include the potential impacts on cost growth of the impact of