David Parnas

David Parnas

Pioneer of software engineering


Dr David Lorge Parnas has been studying industrial software development since 1969.

He has won more than 25 awards for his contributions. In 2007, Parnas was proud to share the IEEE Computer Societyʼs one-time 60th anniversary award with computer pioneer Professor Maurice Wilkes of Cambridge University.

Parnas is a Fellow of the Royal Society of Canada (RSC), the Association for Computing Machinery (ACM), the Canadian Academy of Engineering (CAE), the Gesellschaft für Informatik (GI) in Germany and the IEEE. He is a Member of the Royal Irish Academy.

Parnas is the author of more than 285 publications and reports. Many have been repeatedly republished and are considered classics.


"Software Aging - Why it happens and how to reduce it"


Programs, like people, get old. After they are delivered to customers, various factors make the software become hard to change, slow, and "old fashioned”. This increases costs for the vendor and eventually will drive the product from the market. Many companies become non-competitive as a result of their product aging.

We can’t prevent software aging, but we can understand its causes, take steps to limit its effects, temporarily reverse some of the damage it has caused, and prepare for the day when the software is no longer viable. A sign that the Software Engineering profession has matured will be that we lose our preoccupation with the first release and focus on the long term health of our products. Researchers and practitioners must change their perception of the problems of software development. Only then will Software Engineering deserve to be called Engineering.