Logo Systems Engineering

Terry Bahill, Professor Emeritus
Department of Systems and Industrial Engineering
Department of Biomedical Engineering
University of Arizona


In March 2002 this photograph of Bahill was installed
in the Baseball Hall of Fame exhibit
Baseball As America.
This exhibit was traveling from 2002 to 2008.
Now it is in the Boston Museum of Science.

Bahill holds U.S. patent number 5,118,102 for the Bat Chooser™ a system that computes the Ideal Bat Weight™ for individual baseball and softball batters.
He received the Sandia National Laboratories Gold President's Quality Award.
He is a Fellow of
    • the Institute of Electrical and Electronics Engineers (IEEE),
    • Raytheon Missile Systems,
    • the International Council on Systems Engineering (INCOSE) and
    • the American Association for the Advancement of Science (AAAS).

This directory is for students in Bahill's OLLI classes.

This Excel file contains URLs for sixteenth-century nautical maps.

Chrome might object to downloading this file, saying it is insecure. If it does you can use a different browser or try to tell Chrome that you want to download it anyway.

I have created this directory for students who are using Tradeoff Decisions in System Design by Terry Bahill and Azad Madni, published by Springer, 2017, for a course.

I have created this directory for Instructors who are using Tradeoff Decisions in System Design by Bahill and Madni, published by Springer, 2017, as a textbook for a course. It contains extra homework problems, solutions and PowerPoint slides. The directory is password protected. Faculty can obtain the password by sending a resume and a syllabus for their course that is using this textbook to terry@sie.arizona.edu. The solutions manual for this textbook is also available from Springer.com.ISBN.

Terry Bahill has retired from the University of Arizona.
This list of Bahill's major publications summarizes the research contributions of his career.
Here is a short biographical sketch.

Systems Engineering is an interdisciplinary process that ensures that the customer's needs are satisfied throughout a system's entire life cycle. This process is comprised of the seven following tasks: Stating the problem, Investigating alternatives, Modeling the system, Integrating the system, Launching the system, Assessing performance and Re-evaluation. This process can be summarized with the acronym SIMILAR (Bahill and Gissing, 1998). My What Is Systems Engineering? directory has a paper and a slide show describing the systems engineering process.

Here are abstracts for a series of seminars and short courses that Bahill has given many times world wide.

Bahill has done research on the Science of Baseball. His latest is in the book on the Science of Baseball. If you are interested, go to this baseball directory. Most of these papers were co-authored with Dave Baldwin.
I highly recommend that you read Dave Baldwin's autobiography Snake Jazz. It has some baseball stuff, and it is highly entertaining. His philosophy on life is that, if you lose a game, don't blame society. Just go back and work harder.

Here is a complete set of the eight Wymorian system design documents. They are for the Umpires' Assistant a system that helps the baseball umpire to call balls and strikes.

My Systems Engineering Process is use case based, which means that we start with the use cases, using the use cases we discover the requirements, then we use the use cases to create the test plan.

The following posters describe various aspects of the systems engineering process. You are welcome to use them.

  • A Man with a Hammer (200 Kbytes)

  • A Man with a Hammer (7 Mbytes)

    The phrase "To a man with a hammer everything looks like a nail," is attributed to Mark Twain. We teach students how to use a tool. Then they use that tool for everything. We should teach them to study each problem and then select the best tool for that problem.

  • First Steps of the System Design Process (144 Kbytes)

    The spiral Model for Systems Engineering. The system engineering process starts in the middle with the customers' needs, often described with use cases. Next, we discover requirements. Then, as time progresses, the process spirals outward as we design, build, simulate, verify and validate models. Finally, there is a review and we start all over again, except everything is bigger. This process repeats many times with models, prototypes, pre-production and manufacturing: each of these phases has multiple iterations. Then we have operations, maintenance, retirement and finally replacement.

  • The System Design Process (121 Kbytes)
  • Spiral Model for the System Design Process (1.2 Mbytes)
  • Cost and Influence of Each Phase of the System Life Cycle (40 Kbytes)

    Shadows. The size of each icon indicates the cost of the activity. Discovering requirements costs much less than manufacturing. The size of each shadow indicates the influence of the activity on the design. Discovering requirements has a big influence on the system: whereas, by the time you get to manufacturing, you can change little.

  • Functional Decomposition (98 Kbytes)

    Functional Decomposition. What do we need to fly? For centuries, humans have been unsuccessful in their attempts to fly, because they used physical decomposition (brain, eyes, legs and wings). The Wright Brothers used functional decomposition and focused on three functions: control, horizontal thrust and vertical lift. They flew successfully.

  • Systems Engineering is a Fractal Process (48 Kbytes)
  • Systems Engineering is a Fractal Process. The systems engineering process is applied (at different times and in different places) at levels of different detail. It is applied to the system, the subsystems, the components, etc. Similarly, for the fractal pattern above, the same algorithm was applied at the large structural level, at the medium-scale level and at the fine-detail level, etc. This fractal analogy was created by Bill Nickel at Sandia Laboratories in the summer of 1995.

  • Systems Engineering is the Glue That Holds it all Together (56 Kbytes)
  • Growth of The Systems Engineering Documents (87 Kbytes)
  • Karen's Proper Wine Tasting Technique(1.2 Mbytes)
  • Proper Wine Tasting Technique. First see the wine: behold its color, clarity and legs. Then smell the wine: nose the fruit. Finally, taste the wine and savor the finish: but don't be a dog and slurp it.

  • Terry's Proper Wine Tasting Technique(1.2 Mbytes)
  • Finally,
  • Show your feelings about the wine.(0.8 Mbytes)
  • Here are some carefully worded definitions about systems and states. I had lots of help in writing this.

    This is a masters thesis written by Michael Easton on the topic of complexity. We never published anything from it. It may be in the University of Arizona libary. But I think it is too good to not make it more widely available. So here it is. Michael Easton's thesis on complexity.

    Pinewood contains the complete documentation for the design of a Pinewood Derby. In particular, it has several examples of tradeoff studies. Here is the the Pinewood Derby chapter from Chapman, Bahill, and Wymore.

    Wayne Wymore was the theoretician for our Systems Engineering community. I have his photograph, his autobiography, two of his theoretical papers on Systems Engineering, and a lecture he gave in my class in this directory dedicated to Wymore. Wayne died on February 24, 2011.

    For the lighter side of lexicology, look at my laugh directory.

    Here is a review of the book The Ghost of the Executed Engineer (3 Kbytes).

    This site belongs to Terry Bahill: (520) 742-5469. The last major change was made in February 2024.