A report focuses on the development of flight software (FSW) cost estimates for 16 Discovery-class missions at JPL. The techniques and procedures developed enabled streamlining of the FSW analysis process, and provided instantaneous confirmation that the data and processes used for these estimates were consistent across all missions. The research provides direction as to how to build a prototype rule-based system for FSW cost estimation that would provide (1) FSW cost estimates, (2) explanation of how the estimates were arrived at, (3) mapping of costs, (4) mathematical trend charts with explanations of why the trends are what they are, (5) tables with ancillary FSW data of interest to analysts, (6) a facility for expert modification/ enhancement of the rules, and (7) a basis for conceptually convenient expansion into more complex, useful, and general rule-based systems.
This work was done by John N. Spagnuolo, Jr. and Sherry A. Stukes of Caltech for NASA’s Jet Propulsion Laboratory.
This software is available for commercial licensing. Please contact Dan Broderick at
This Brief includes a Technical Support Package (TSP).
On a Formal Tool for Reasoning About Flight Software Cost Analysis
(reference NPO-48487) is currently available for download from the TSP library.
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Overview
The document is a Technical Support Package from NASA, specifically focused on a formal tool for reasoning about flight software cost analysis, referenced as NPO-48487. It aims to disseminate the results of aerospace-related developments that have potential technological, scientific, or commercial applications. The document is part of NASA's Commercial Technology Program and is intended to support innovative partnerships.
The outline of the document includes several key sections: background information, a knowledge engineering approach, decision graphs, initial input data for SEER-SEM (a software estimation tool), and a summary of estimate results. The background section discusses the specific application of the software estimates provided for proposals under tight schedule constraints and limited resources, highlighting the challenges faced by a small team of analysts.
The knowledge engineering approach emphasizes the importance of trusting knowledge bases (KBs) that establish model parameter settings. It advises making modifications cautiously, focusing on cost drivers, and documenting any adjustments made to reflect uncertainty in the estimates. This approach is crucial for ensuring the reliability of cost estimations in aerospace projects.
The decision graph is a significant component of the cost estimating process, serving as a visual representation that aids in understanding the relationships between various parameters and their impact on cost. The document also discusses the initial input data required for SEER-SEM, including mission type, developer information, and decision dynamics related to quantitative parameter determination.
A spreadsheet summary is provided, which serves as a single source for compiling cost data across all proposals. This spreadsheet consists of descriptive, size, and attribute data, allowing for quick relative comparisons of input data and output results. It is noted that this spreadsheet preceded and informed the development of the decision graph.
In conclusion, the document encapsulates a structured approach to flight software cost analysis, integrating knowledge engineering principles and decision-making tools to enhance the accuracy and reliability of cost estimates in aerospace projects. It serves as a resource for proposal cost engineers and highlights the importance of thorough documentation and cautious modifications in the estimation process. For further inquiries or assistance, contact information for NASA's Innovative Technology Assets Management is provided.
