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Executive Summary
Pages 1-16

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From page 1...
... The first issue the Committee was asked to consider was He Shuttle program's decision to eliminate Me independent verification and validation OV&V) function currently performed on the Shuttle flight software at an annual cost of $3.2 million (out of approximately $100 million per year for the complete software development and assurance process)
From page 2...
... Therefore, the Committee does not support NASA's plan to eliminate funding for the IV&V effort in fiscal year 1993. The Committee believes Hat He Space Shuttle software development process is not adequate without IV&V and Cat elimination of IV&V as currency practiced will adversely affect He overall quality and safety of the software, both now and in the future.
From page 3...
... NASA Guidelines and Standards Flading #I: Each software development contractor provides its own development and coding guidelines for the Shuttle software. These guidelines are not consistent among the developers.
From page 4...
... Software V&V Finding #3: V&V inspections by software development contractors focus on verifying the consistency of two descriptions at different levels of detail (e.g., consistency between a modules requirements and the design of its implementation)
From page 5...
... NASA's descnpbon of its software development process states that the responsibility for requirements belongs to the flight software community, where the community seems to be composed of everyone having anything to do with the software. This is obviously not adequate from either a managerial or technical standpoint and better system-level V&V processes for software requirements need to be put In place.
From page 6...
... Recommendation #4: In order to provide a greater level of independence, responsibility for IV&V should be vested in entities separate from the Shuttle program structure aru! the centers involved in the Shuttle software development and operation.
From page 7...
... Reeom~nendation #5: NASA should establish arm adopt standards for software safety and apply them as much as possible to Shuttle software upgrades. The standards should be applied in full to new projects such as the space station.
From page 8...
... Recommendation #a: NASA should persons a hazard analysis for the Shuttle software, as describe in the draft software safety guideline. NASA should also implernen~ the other appropriate aspects of the draft software safety guideline (testing, change hazard analysis, and system-safety requirements traceability)
From page 9...
... Finally, more emphasis in the Aerospace Safety Advisory Panel on software issues, perhaps in the form of a special subcommittee to consider software safety issues, would demonstrate and give visibility to NASA's understanding of the growing importance of software to the safe accomplishment of 7 The term dotted-tine is often used to describe two organizations between which there is no formal line of authority. The term Ingrates from organization charts that have a solid line to indicate forums reporting relationships and dotted lines to indicate less formal relationships.
From page 10...
... The Shuttle Program Office has recently attempted to document the software V&V process to provide some visibility into Be software maintenance and upgrade process as a whole. This was a good first step and has been valuable in helping the Committee understand the roles and relationships of the venous organizations that participate.
From page 11...
... By undertaking an exercise to better understand and document the current process, Be Shuttle program may, independency of the other findings and recommendations of this committee, discover areas where the process could be streamlined to reduce cost without adversely affecting safety and performance. Recommendation #12: NASA should coni`ru~e to enhance the current effort totally document ad aspects of the Shuttle flight software process.
From page 12...
... For example, the Committee was told that those responsible for tracking software errors at NASA headquarters do not have routine access to the same data bases that the center and contractor personnel use. The Committee questions the need for multiple data bases Racking software error information because it could lead users to lose, confuse, or simply ignore valuable information.
From page 13...
... The Rogers Commission pointed to this type of community responsibility as one of the factors that contributed to the Challenger accident. Recommendation #16: NASA should assign specific responsibilit~esfor each aspect of theflight software process awl document them accordingly.
From page 14...
... Recommendation #19: NASA should underage an effort to capture the lessons iearrze~ in the development, maintenance, and assurance of the Shuttle flight software for use ~ other programs. This not only should take the form of official ~oc~nentation of the current process, but also should include less formal reports, observations, and opinions drawn from current personnel arm as many former Shuttle program arm contractor m~nagemera and technicalpersonne!
From page 15...
... This same problem is likely to occur in future programs. For example, the GAO has expressed some of the same concerns about the Space Station's software development process as expressed by all of the groups' including this committee, that have examined the Shuttle program.
From page 16...
... However, there is no single prime contractor Mat is responsible for integrating an the software nor is an IV&V effort planned. To bring the Space Station software effort and others such as the Earth Observing System Data and Information System to a successful completion, NASA will need to design and implement aggressive software development and software system safety programs using state-of-the-art technology and leading edge methodologies.


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