Vijay K. Vaishnavi

On theory development in design science research: anatomy of a research project

The common understanding of design science research in information systems (DSRIS) continues to evolve. Only in the broadest terms has there been consensus: that DSRIS involves, in some way, learning through the act of building. However, what is to be built – the definition of the DSRIS artifact – and how it is to be built – the methodology of DSRIS – has drawn increasing discussion in recent years. The relationship of DSRIS to theory continues to make up a significant part of the discussion: how theory should inform DSRIS and whether or not DSRIS can or should be instrumental in developing and refining theory. In this paper, we present the exegesis of a DSRIS research project in which creating a (prescriptive) design theory through the process of developing and testing an information systems artifact is inextricably bound to the testing and refinement of its kernel theory.

On computing mobile agent routes for data fusion in distributed sensor networks

The problem of computing a route for a mobile agent that incrementally fuses the data as it visits the nodes in a distributed sensor network is considered. The order of nodes visited along the route has a significant impact on the quality and cost of fused data, which, in turn, impacts the main objective of the sensor network, such as target classification or tracking. We present a simplified analytical model for a distributed sensor network and formulate the route computation problem in terms of maximizing an objective function, which is directly proportional to the received signal strength and inversely proportional to the path loss and energy consumption. We show this problem to be NP-complete and propose a genetic algorithm to compute an approximate solution by suitably employing a two-level encoding scheme and genetic operators tailored to the objective function. We present simulation results for networks with different node sizes and sensor distributions, which demonstrate the superior performance of our algorithm over two existing heuristics, namely, local closest first and global closest first methods.

Predicting maintenance performance using object-oriented design complexity metrics

The Object-Oriented (OO) paradigm has become increasingly popular in recent years. Researchers agree that, although maintenance may turn out to be easier for OO systems, it is unlikely that the maintenance burden will completely disappear. One approach to controlling software maintenance costs is the utilization of software metrics during the development phase, to help identify potential problem areas. Many new metrics have been proposed for OO systems, but only a few of them have been validated. The purpose of this research is to empirically explore the validation of three existing OO design complexity metrics and, specifically, to assess their ability to predict maintenance time. This research reports the results of validating three metrics, Interaction Level (IL), Interface Size (IS), and Operation Argument Complexity (OAC). A controlled experiment was conducted to investigate the effect of design complexity (as measured by the above metrics) on maintenance time. Each of the three metrics by itself was found to be useful in the experiment in predicting maintenance performance.

Informal and formal requirements specification languages: bridging the gap

The differences between informal and formal requirements specification languages are noted, and the issue of bridging the gap between them is discussed. Using structured analysis (SA) and the Vienna development method (VDM) as surrogates for informal and formal languages, respectively, two approaches are presented for integrating the two. The first approach uses the SA model of a system to guide the analysts understanding of the system and the development of the VDM specifications. The second approach proposes a rule-based method for generating VDM specifications from a set of corresponding SA specifications. The two approaches are illustrated through a simplified payroll system case. The issues that emerge from the use of the two approaches are reported. >

Product metrics for object-oriented systems

We survey metrics proposed for object-oriented systems, focusing on product metrics. The survey is intended for the purposes of understanding, classifying, and analyzing ongoing research in object-oriented metrics. The survey applies fundamental measurement theory to artifacts created by development activities. We develop a mathematical formalism that captures this perspective clearly, giving appropriate attention to the peculiarities of the object-oriented system developmenr process. Consistent representation of the available metrics, following this mathematical formalism, shows that current research in this area contains varying coverage of different products and their properties at different development stages. The consistent representation also facilitates several analyses including aggregation across metrics, usage across metrics, equivalent formulation of metrics by multiple researchers, and exploitation of traditional metrics for object-oriented metrics. We also trace the chronological development of research in this area, and uncover gaps that suggest opportunities for future research.

On efficient deployment of sensors on planar grid

One practical goal of sensor deployment in the design of distributed sensor systems is to achieve an optimal monitoring and surveillance of a target region. The optimality of a sensor deployment scheme is a tradeoff between implementation cost and coverage quality levels. In this paper, we consider a probabilistic sensing model that provides different sensing capabilities in terms of coverage range and detection quality with different costs. A sensor deployment problem for a planar grid region is formulated as a combinatorial optimization problem with the objective of maximizing the overall detection probability within a given deployment cost. This problem is shown to be NP-complete and an approximate solution is proposed based on a two-dimensional genetic algorithm. The solution is obtained by the specific choices of genetic encoding, fitness function, and genetic operators such as crossover, mutation, translocation for this problem. Simulation results of various problem sizes are presented to show the benefits of this method as well as its comparative performance with a greedy sensor placement method.

Rectilinear line segment intersection, layered segment trees, and dynamization☆

Abstract The aim of the present paper is to provide an efficient solution to the following problem: “Given a family of n rectilinear line segments in two-space report all intersections in the family with a query consisting of an arbitrary rectilinear line segment.” We provide an algorithm which takes O ( n log 2 n ) preprocessing time, o ( n log 2 n ) space and O (log 2 n + k ) query time, where k is the number of reported intersections. This solution serves to introduce a powerful new data structure, the layered segment tree, which is of independent interest. Second it yields, by way of recent dynamization techniques, a solution to the on-line version of the above problem, that is the operations INSERT and DELETE and QUERY with a line segment are allowed. Third it also yields a new nonscanning solution to the batched version of the above problem. Finally we apply these techniques to the problem obtained by replacing “line segment” by “rectangle” in the above problem, giving an efficient solution in this case also.

The emergence of design research in information systems in North America

Information Systems (IS) is a relatively new field of study that investigates information and communications technology (ICT) in organisational settings. Originally a branch of management science, IS became an independent field in the late 1960s. Only recently in North America has IS design research (ISDR) become a distinct line of inquiry within the field. This paper details the emergence of ISDR within North American IS research and outlines its current state. ISDR, as currently conceived in North America, is narrower in scope than design research in fields where it has a longer history. With reference to the literature, we expose directions of research highly germane to ISDR that are precluded by the current common understanding, which requires an artefact as the output of all design research efforts. We propose suggestions for relaxing this constraint on research output while still retaining a focus on research relevance and ICT artefacts.

Facilitating experience reuse among software project managers

Organizations have lost billions of dollars due to poor software project implementations. In an effort to enable software project managers to repeat prior successes and avoid previous mistakes, this research seeks to improve the reuse of a specific type of knowledge among software project managers, experiences in the form of narratives. To meet this goal, we identify a set of design principles for facilitating experience reuse based on the knowledge management literature. Guided by these principles we develop a model called Experience Exchange for facilitating the reuse of experiences in the form of narratives. We also provide a proof-of-concept instantiation of a critical component of the Experience Exchange model, the Experience Exchange Library. We evaluate the Experience Exchange model theoretically and empirically. We conduct a theoretical evaluation by ensuring that our model complies with the design principles identified from the literature. We also perform an experiment, using the developed instantiation of the Experience Exchange Library, to evaluate if technology can serve as a medium for transferring experiences across software projects.

Data structures for the rectangle containment and enclosure problems

Abstract The containment and enclosure problems for rectangles are studied. Efficient data structures are given for the restricted rectangle containment and enclosure problems. Based on these data structures, algorithm for these problems are given which run in optimal time and use O(n log n) space inthe worst case. A generalization of thee data structures and algorithms leads to o(n log2 n) space and O(n log2 n + k) time worst-case) algorithms for the (general) rectangle containment and enclosure problems The algorithms for the restricted rectangle and the (general) rectangle containment problems are combined leading to a new algorithm for the rectangle containment problem with O(n log n) space and O(n log n + k) time worst case performance when the given set of rectangles contains a much higher proportion of restricted rectangles. Throughout, the duality of the problems tackled and the duality of the data structures and the algorithms given are emphasized.