QRS 2021 Keynote Speech 1

The Temptation of Searching for the Best–Balancing Validity
and Optimality in Software Engineering


Software engineering is a decision-centric discipline. Decisions have to be made about people, processes, and artifacts at all stages of the software life cycle. But what does it mean to search for the best option? Technically, this problem is approached by optimization, being an established discipline and aiming to find the best solution(s) under given constraints and objectives. But the problem is not so much a technical one, but more an issue of validity. Data and models in Software Engineering are highly uncertain. Aristotle (384 to 322 BC) stated, “It is the mark of an educated mind to rest satisfied with the degree of precision which the nature of the subject admits and not to seek exactness where only an approximation is possible.”
Optimizing Software Engineering is tempting and is the content of many publications. We maximize value, reliability, security, and we minimize risk or cost. From all that, some follow-up questions are: How valuable is this optimality? How valid is the result? How much should we invest into it? The talk explores the problem, goes through some examples, and tries to provoke discussion overall.


Guenther Ruhe's avatar
Prof. Guenther Ruhe Canada


University of Calgary

Guenther Ruhe is the Industrial Research Chair in Software Engineering at the University of Calgary. This is a joint position between the Department of Computer Science and the Department of Electrical and Software Engineering at the University of Calgary. Before coming to Calgary, he was deputy director of the Fraunhofer Institute for Experimental Software Engineering Fh IESE, Germany. He won various awards such as the Alberta iCORE (Informatics Center of Research Excellence) award, an IBM research award, and a Microsoft Research Software Engineering Innovation award. Since 2016, he has served as the Editor in Chief of the journal of Information and Software Technology, published by Elsevier. His main research interests are in the areas of Product Release Planning, Software Project Management, Decision Support, Open Innovation, Data Analytics, Empirical Software Engineering as well as Search-based Software Engineering. He is a Senior Member of IEEE and a member of the ACM. Prof. Ruhe is the Founder and CEO of Expert Decisions Inc. as well, which is a University of Calgary spin-off company.