Improving The Software Upgrade Value Stream

*† This paper reports findings from a two-year study to identify Lean practices for deriving software requirements from aerospace system level requirements, with a goal towards improving the software upgrade value stream. The study was undertaken as part of the MIT Lean Aerospace Initiative. Three detailed case studies and 128 surveys collected from ten “successful” mission critical aerospace software upgrade programs support seven major findings. I. Background The Lean Aerospace Initiative (LAI) is a government, industry, labor, and academic consortium focused on identifying and implementing the principles of Lean in the aerospace industry. Lean originated in the automotive industry and is grounded in the manufacturing domain. To the authors’ knowledge, this is the first research specifically designed to apply the Lean principles and the Lean Enterprise Model to the process of deriving aerospace software requirements. The basic principles of Lean are focused on employing value added activities to reduce product cycle time, increase quality, reduce cost, and increase stakeholder satisfaction. Deriving software requirements are an important step in developing aerospace software products. Requirement derivation activities occur early in the product development process and can have significant impacts on the cost, schedule, and performance of the system 3 . The cost to correct errors made early in the phases of product development grows exponentially the longer they go undetected 4 . Analyzing the requirement process using a Lean framework allows practitioners the opportunity to improve the process to reduce the possibility of adverse system impacts. The Lean Enterprise Model (LEM) 5 is a framework that incorporates enterprise level lean principles and practices, together with supporting data. This research utilized the LEM framework to identify the presence of Lean practices in the process of deriving software requirements on real time mission critical aerospace systems. LEM enterprise level metrics (Flow Time, Stakeholder Satisfaction, Quality Yield, and Resource Utilization) were used to develop process outcome measures. The twelve Overarching Practices identified in the LEM 5 were used as a guide for analyzing the presence of effective Lean practices for deriving software requirements. The findings identified in this paper are the product of a comprehensive two-year research effort 1,2 involving three detailed case studies consisting of 45 interviews, in support of 128 stakeholder surveys collected from 10 aerospace systems, feedback from numerous aerospace industry practitioners, and Massachusetts Institute of Technology faculty and students. All 10 aerospace systems were real-time mission critical software upgrades representing four application domains (military aircraft, military space ground terminal, commercial aircraft, and missile/munitions). LAI industry and government consortium members selected the systems involved in the research effort. Each system is believed to be one that had a successful derivation of software requirements. Table 1 summarizes some of the discriminatory characteristics of the systems used in the research.