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Estimation of Expedited Systems Engineering Schedules

Software/Hardware Track



A major objective of many organizations is to reduce the calendar time needed for a project to perform its systems engineering (SE) functions, without compromising the resulting product’s needed functionality and quality attributes. This paper will present the derivation of a model to estimate the necessary calendar time to perform the project’s SE functions as a function of its product drivers (size, domain familiarity), process drivers (maturity, streamlining), project drivers (team cohesion, collaboration technology support), people drivers (knowledge, skills, and agility), and risk drivers (vs. relative needs for speed, quality, and scalability).

The baseline schedule estimation model is derived from the classic cube-root schedule estimation model shared by most software models and data from the intgrated circuit industry, plus data from Tan’s activity-distribution analysis of the DoD Software Resources Data Report data. Tan showed this to be domain-dependent, ranging from 31% due to Requirements, Architecting, and Design for Mission Planning applications to 42% for Business applications.

The schedule drivers above used to modify the baseline schedule estimateare derived from an SE re-analysis of the software CORADMO schedule drivers and their associated Rapid Development Opportunity Tree defined in “Software Cost Estimation with COCOMO II,” Boehm et al., Prentice Hall, 2000.

The resulting model enables organizations not only to estimate and perform tradeoff analyses for a project’s SE calendar time, but also to use the schedule drivers as guides for an organization to reduce the amount of project time it spends doing SE.


Barry Boehm
Barry W. Boehm is the TRW Professor of Software Engineering; Founding Director Emeritus, Center for Systems and Software Engineering; and Director of Research, DoD-Stevens-USC Systems Engineering Research Center; in the Computer Science and Industrial and Systems Engineering Departments of the University of Southern California. He is also a part-time employee of the Aerospace Corp. He received his B.A. degree from Harvard in 1957, and his M.S. and Ph.D. degrees from UCLA in 1961 and 1964, all in Mathematics. He has also received honorary Sc.D.s in Computer Science from the U. of Massachusetts in 2000 and in Software Engineering from the Chinese Academy of Sciences in 2011.

Between 1989 and 1992, he served within the U.S. Department of Defense (DoD) as Director of the DARPA Information Science and Technology Office, and as Director of the DDR&E Software and Computer Technology Office. He worked at TRW from 1973 to 1989, culminating as Chief Scientist of the Defense Systems Group, and at the Rand Corporation from 1959 to 1973, including direction of major command and control systems analyses and culminating as Head of the Information Sciences Department. He was a Programmer-Analyst at General Dynamics between 1955 and 1959.

While at USC, he has served as the Principal Investigator on major research contracts and grants from the Office of the Secretary of Defense, DARPA, ONR, AFRL, USAF-ESC, TACOM, NASA, FAA, and NSF. He has received industry research grants from over 25 industrial organizations. His real-client software engineering project course has successfully completed over 200 projects for USC-neighborhood clients and educated over 2000 students in an integrated approach to systems engineering and software engineering.

His current research interests focus on value-based systems and software engineering, including a new process model, the Incremental Commitment Spiral Model, for integrating a system’s hardware, software, and human factors across its definition, design, development, and evolution life cycle. His contributions to the field include the Constructive Cost Model (COCOMO) family of parametric estimation models, the Spiral Model of the software process, the Theory W (win-win) approach to systems and software management and requirements determination, and the foundations for the areas of software risk management and software quality factor analysis.
He has served on the boards of several scientific journals, and as founding Chair of the AIAA Technical Committee on Computer Systems, Chair of the IEEE Technical Committee on Software Engineering, and as a member of the Governing Board of the IEEE Computer Society. He has also served as Chair of the Air Force Scientific Advisory Board’s Information Technology Panel, Chair of the NASA Research and Technology Advisory Committee for Guidance, Control, and Information Processing, and Chair of the Board of Visitors for the CMU Software Engineering Institute.

His honors and awards include Guest Lecturer of the USSR Academy of Sciences (1970), the AIAA Information Systems Award (1979), the J.D. Warnier Prize for Excellence in Information Sciences (1984), the ISPA Freiman Award for Parametric Analysis (1988), the NSIA Grace Murray Hopper Award (1989), the Office of the Secretary of Defense Award for Excellence (1992), the ASQC Lifetime Achievement Award (1994), the ACM Distinguished Research Award in Software Engineering (1997), the IEEE Harlan D. Mills Award (2000), Visiting Professor of the Chinese Academy of Sciences (2005), Best Paper of 2006 award from the INCOSE journal Systems Engineering, Lifetime Achievement Symposium honoree in Software Engineering Education (2006) and Software Engineering (2007), the IEEE Simon Ramo Medal in systems science and engineering (2010), and the Wayne Stevens Lifetime Achievement Award in Software Engineering (2011). He is a Fellow of the primary professional societies in computing (ACM), aerospace (AIAA), electronics (IEEE), and systems engineering (INCOSE), and a member of the U.S. National Academy of Engineering.

Jo Ann Lane
University of Southern California 
Jo Ann Lane is a research assistant professor at the University of Southern California Center for Systems and Software Engineering, conducting research in the areas of software engineering, systems engineering, and system of systems engineering (SoSE). She was a co-author of the 2008 Department of Defense Systems Engineering Guide for Systems of Systems. Current areas of research include system and system capability affordability, expediting systems engineering, balancing lean and agile techniques with technical debt, SoSE processes, SoSE cost modeling, analysis of SoSE with respect to lean principles, system of systems (SoS) interoperability, SoSE test and evaluation, system development feasibility assessments, and innovation in systems engineering. She has published over 20 papers in the SoS area, several of which are widely referenced in the SoS literature. She is also an emeritus professor in the Computer Science Department at San Diego State University where she continues to teach an occasional course in software engineering, software measurement, and software management. In addition, she is currently a member of the INCOSE and IEEE professional organizations and Past President of the San Diego, CA INCOSE Chapter. Prior to her current work in academia, she was a key technical member of Science Applications International Corporations Software and Systems Integration Group for over 20 years, responsible for the development and integration of software-intensive systems and systems of systems and instrumental in establishing the corporate software measurement repository. She received her PhD in systems engineering from the University of Southern California and her Masters in computer science from San Diego State University.

Dan Ingold