Vaishnavi has mainly been on the faculty of Georgia State University and has also held faculty positions at a number of other universities in India, Canada, and the US such as Birla Institute of Technology and Science, Pilani ; Indian Institute of Technology Kanpur; Concordia University; and Ohio University. He has conducted the bulk of his research and scholarly work at the Computer Information Systems department of Georgia State University; he joined the department as an associate professor in 1981 and became a full professor in 1987, board of advisors professor in 2005, and professor emeritus in 2014. Over these years the GSU CIS department has gained considerable reputation; its research and academic programs are very highly ranked.
Vaishnavi has made major contributions to the teaching, propagation, and development of design science research methods for information systems and other information and communication technology fields such as computer science, software engineering, and human-computer interface. Starting in early 1990s, he started focusing his doctoral level seminar course to design science research methods, which he then called "improvement research" taking the novel approach of developing a pattern language for conducting this type of research. This work resulted in the introduction of a formal course for the teaching of this type of research in 2002 called "Design Science Research Methods in Information Systems," creation of the living AIS design science research page in 2004, last revised in 2019, and publication of the book: Design Science Research Methods and Patterns in 2007, which has been widely used as a reference or textbook; the second revised and expanded edition of this book has been published in 2015. In addition to contributing to design science research methods, he has also contributed to advancing design science theory through his books as well as research papers including the recent EJIS paper and the JAIS paper.
Software engineering
In this area Vaishnavi has contributed to facilitating the use of object technology by major companies in addition to making interesting research contributions in a number of subareas of software engineering. Between 1992 and 1998, he worked as a founding research director. His research contributions to software engineering include models and frameworks for the use of formal specifications, a data/knowledge paradigm for the development of operations support systems, and a comprehensive survey and framework for object-oriented product metrics.
The work of Vaishnavi in this area has mainly focused on computational geometry problems and the creation of efficient new data structures for multidimensional and weighted data. In the computational geometry area, Vaishnavi was among early researchers who developed and used techniques for efficiently locating a key in many ordered lists—a problem that frequently arises in computational geometry. In this regard, Mehlhorn and Näher write that several researchers including Vaishnavi and Wood "observed that the naïve strategy of locating the key separately in each list by binary search is far from optimal and that more efficient techniques frequently exist." They further write that Chazelle and Guibas "distilled from these special case solutions a general data structuring technique and called it fractional cascading." Vaishnavi's work on efficient multidimensional and weighted data structures include creation and analysis of new data structures such as multidimensional height-balanced trees, multidimensional balanced binary trees, and weighted leaf AVL-trees. These data structures generalize known structures for one dimensional data to higher dimensions or weighted data while offering optimal performance.
