Examples of Mental Mistakes Made by Systems Engineers While Creating Tradeoff Studies

Abstract

Problem statement: Humans often make poor decisions. To help them make better decisions, engineers are taught to create tradeoff studies. However, these engineers are usually unaware of mental mistakes that they make while creating their tradeoff studies. We need to increase awareness of a dozen specific mental mistakes that engineers commonly make while creating tradeoff studies.

Aims of the research: To prove that engineers actually do make mental mistakes while creating tradeoff studies. To identify which mental mistakes can be detected in tradeoff study documentation.

Methodology: Over the past two decades, teams of students and practicing engineers in Bahill’s Systems Engineering courses wrote the system design documents for an assigned system. On average, each of these document sets took 100 man-hours to create and comprised 75 pages. We used 110 of these projects, two dozen government contractor tradeoff studies and three publicly accessible tradeoff studies. We scoured these document sets looking for examples of 28 specific mental mistakes that might affect a tradeoff study. We found instances of a dozen of these mental mistakes.

Results: Often evidence of some of these mistakes cannot be found in the final documentation. To find evidence for such mistakes, the experimenters would have had to be a part of the data collection and decision making process. That is why, in this paper, we present only 12 of the original 28 mental mistakes. We found hundreds of examples of such mistakes. We provide suggestions to help people avoid making these mental mistakes while doing tradeoff studies.

Conclusions: This paper shows evidence of a dozen common mental mistakes that are continually being repeated by engineers while creating tradeoff studies. When engineers are taught about these mistakes, they can minimize their occurrence in the future.