David Parnas
David Lorge Parnas (born
February 10,
1941) is an early pioneer of
software engineering who developed the concept of module design which is the foundation of
object oriented programming today. He is also noted for his advocacy of technical realism.
David earned his
Ph.D. at
Carnegie Mellon University in
electrical engineering and worked there as a professor for many years. He also taught at the
University of North Carolina at Chapel Hill (
USA), the
Technische Hochschule Darmstadt (
Germany), the
University of Victoria (
British Columbia,
Canada), and
Queen's University (
Ontario,
Canada.) He then went to
McMaster University in
Hamilton,
Ontario,
Canada in
1991. Since 2002, David has worked at the
University of Limerick in
Limerick,
Ireland. Parnas also earned a professional engineering license in Canada and was one of the first to apply traditional engineering principles to software design.
In modular design his double dictum of high cohesion within modules and loose coupling between modules is fundamental to modular design in software. This concept was introduced in Parnas's seminal
1972 paper
On The Criteria To Be Used in Decomposing Systems into Modules.
Dr. Parnas took a public stand against the
US Strategic Defense Initiative (also known as "Star Wars") in the mid
1980s, arguing that it would be impossible to write an application of sufficient quality that it could be trusted to prevent a nuclear attack. He has also been in the forefront of those urging the professionalization of "
software engineering" (a term that he characterizes as "an unconsummated marriage"). Dr. Parnas is also a heavy promoter of ethics in the field of software engineering.
*
ACM "Best Paper" Award,
1979*Two "Most Influential Paper" awards
International Conference on Software Engineering (date unknown)
*
Doctor honoris causa of the Faculté des Sciences Appliquées,
Université catholique de Louvain,
Belgium,
1996*
ACM SIGSOFT's "Outstanding Research" award,
1998...it is almost always incorrect to begin the decomposition of a system into modules on the basis of a flowchart. We propose instead that one begins with a list of difficult design decisions or design decisions which are likely to change. Each module is then designed to hide such a decision from the others.I would advise students to pay more attention to the fundamental ideas rather than the latest technology. The technology will be out-of-date before they graduate. Fundamental ideas never get out of date. However, what worries me about what I just said is that some people would think of Turing machines and Goedel's theorem as fundamentals. I think those things are fundamental but they are also nearly irrelevant. I think there are fundamental design principles, for example structured programming principles, the good ideas in "Object Oriented" programming, etc.*
McMaster University homepage*
University of Limerick profile and
CV (
PDF)
*
On The Criteria To Be Used in Decomposing Systems into Modules *
Software Fundamentals: Collected Papers by David L. Parnas at Addison Wesley online bookstore
