News About George Rebovich

Systems Engineering in Practice Captured in MITRE Guide

  • Nov 02, 2012 |

    Systems engineering is a discipline in which almost every assignment includes challenges not encountered before, so learning is an essential part of every systems engineer's career. (If you are new to systems engineering, check out "What Is Systems Engineering?" below.)

    While textbooks provide a good foundation for systems engineering principles, what's also needed to make it work is the know-how of experienced, hands-on practitioners. Now, with the public rollout of the MITRE Systems Engineering Guide (SEG) that crucial practical knowledge is available in one place. The SEG can be accessed online anytime and is available without charge.

    "Much of this information is not available in textbooks," says George Rebovich, director of MITRE's Systems Engineering Practice Office, who led the development of the SEG. "The SEG is not a replacement for knowledge gained in a classroom. It supplements that experience with best practices and lessons learned for dealing with difficult, commonly encountered situations in applying systems engineering principles."

    The SEG represents the collected wisdom of 130 MITRE technical staff, organized into more than 100 articles. Topics range from the classical systems engineering building blocks, like system design and development, to the emerging discipline of engineering information-intensive enterprises.

    The SEG was originally developed for MITRE staff performing in its federally funded research and development center (FFRDC) systems engineering role. It quickly became clear, however, that the SEG had value for the wider systems engineering community, including government program managers and engineers, commercial contractors, academia, and other FFRDCs. Rebovich likens systems engineering to a team sport—to succeed you need to cooperate, collaborate, and share what you know with all team members.

    Objective Guidance

    The articles in the SEG don't promote specific technologies, products, or processes. Instead, they focus on getting the job done right by using all the facets of systems engineering—the technical ones as well as elements such as organizational change and economic factors.

    What Is Systems Engineering?

    The complexity of federal enterprises requires a spectrum of systems engineering techniques.

    While the term systems engineering can be traced back at least to the 1940s, to this day no single, universal definition of the term exists. Frequently, systems engineering is defined by the context in which it is embedded. One definition of the classical practice of systems engineering (from the National Academies) is, "an interdisciplinary approach to translating users' needs into the definition of a system, its architecture and design through an iterative process that results in an effective operational system. Systems engineering applies over the entire life cycle, from concept development to final disposal."

    Enterprise engineering focuses on the ability of individual systems, the network of constantly changing systems, and their users to adapt to changes in their environment. It employs techniques that draw on the fundamental principles of evolution, ecology, and adaptation to increase the likelihood of favorable outcomes in complex environments that may change in unpredictable ways. It requires skills in designing for options and composability, strategies for early and continuous discovery, and strategies tailored to the volatility of user requirements and enabling technologies.

    Enterprise engineering is not a replacement for classical systems engineering. Increasingly, both disciplines must be used in combination to achieve success.


    "In the real world, projects usually do not unfold as planned," Rebovich says. "But when you're working on a large-scale, complex program, certain problems can generally be expected to crop up. We wanted to provide guidance on what you can do to mitigate or work around frequently encountered obstacles when they do arise."

    Rebovich credits MITRE's Corporate Chief Engineer, Lou Metzger, with conceiving the idea for the SEG. "Lou had a clear vision of what it should be—a resource that provides real-world lessons learned. That's the kind of guidance that's often not written down anywhere but which you wish you could find," Rebovich says.

    There's Little Routine in Systems Engineering

    "Systems engineering is such a broad, deep and expanding field—no one can possibly know everything," he adds. "Every time you get a new job, what's the likelihood that you'll say 'been there, done that, I know exactly what to do'? That hardly ever happens.

    "So what do you do when you get a new assignment? You ask: 'Who's an expert on this aspect of systems engineering that I can speak with about common problems and pitfalls, best practices, and lessons learned?' But it's hard to get an hour of an expert's time.

    "To address that problem, we asked MITRE experts to sit down long enough to put what's in their heads into these articles. And now systems engineering practitioners and researchers around the world can access that information when they need it."

    Reflecting the Best and Brightest

    Given the expansive nature of systems engineering, no company—not even one with deep roots in the field like MITRE—can know everything. The SEG reflects this reality.

    "Take the article that covers CMMI [Capability Maturity Model Integration, a specific area relating to system development]," Rebovich explains. "Many of the references are not from MITRE, they're from Carnegie-Mellon's Software Engineering Institute—they're recognized experts in CMMI, and they operate an FFRDC related to advanced software technology.

    "We know that for many topics, there are experts throughout the profession—in the government, academia, and industry. Although most of the guide has been generated by MITRE, the intellectual content attempts to reflect the knowledge of the best and brightest, wherever it exists."

    Hard-Won Experience Informs Solutions

    Lou Metzger, initiator of the SEG, explains that he wanted each article to be written in a certain way. "I wanted each expert to ask: In this area, what are the tight corners, pitfalls, and conundrums you typically encounter? And then I wanted them to answer that question by providing the lessons learned they use to help get out of those tight corners. That's what we were looking for—crisp articulations of best practices based on real-world experience."

    He notes that by presenting the information in an easily accessible format and location, the SEG can help answer commonly encountered questions, which in turn saves the government time and money.

    Rebovich says that he can empathize with young or inexperienced systems engineers faced with new, unfamiliar situations. When he started at MITRE many years ago on the Airborne Early Warning and Control System (AWACS) program, he notes that he made rookie errors because he lacked some crucial knowledge—in one case, about important differences between a technical prototype and a product demonstration.

    "I contributed to the SEG article on competitive prototyping based on my own experience, including that first assignment," he says. "I'd like to think that if I'd read the SEG article on prototyping back then, I'd have been better prepared." (As the article explains, a demonstration can be scripted to perform a few things well when conducted by a knowledgeable person. A prototype should have the essential technical attributes of the end product. It should have the ability to be operated without a script by a domain expert with very little experience with the prototype.)

    "I can easily see a less experienced engineer in the same situation today. The technology changes, but the essentials are similar. We hope people can use the SEG to move up their learning curve quickly and side-step potential obstacles to success."

    Systems Engineering Never Sleeps

    Given the large amount of accumulated knowledge in the SEG, why not produce it as a textbook?

    "We chose not to publish the SEG as a book so we can more readily build on and expand the guidance," Metzger says. "Systems engineering is evolving, and the community is continuously adding to its knowledge to reflect new challenges and solutions to them. We want to put out wisdom as we learn and understand it, so we're always in the process of adding more articles. While much systems engineering wisdom persists over decades, by creating the SEG in this way, we can incorporate new information more readily."

    "For example, we're now working on a section on systems engineering for mission assurance," he says. "Aspects of that discipline, like engineering for cyber mission assurance, are relatively new and rapidly evolving—and are very important to our nation's security. That's the kind of topic where we can't just do systems engineering as we understood it 50 years ago."

    Rebovich welcomes feedback on the SEG from systems engineers, acquisition specialists, researchers, and others who use the site. To ask questions or make a comment, please contact us.

    About The MITRE Corporation

    The MITRE Corporation is a not-for-profit organization that provides systems engineering, research and development, and information technology support to the government. It operates federally funded research and development centers for the Department of Defense, the Federal Aviation Administration, the Internal Revenue Service and Department of Veterans Affairs, the Department of Homeland Security, the Administrative Office of the U.S. Courts, and the Centers for Medicare & Medicaid Services, with principal locations in Bedford, Mass., and McLean, Va.  To learn more, visit http://www.mitre.org/.