Daniel E. Turk

Assumptions Underlying Agile Software-Development Processes

Agile processes focus on the early facilitation and fast production of working code, and are based on software-development process models that support iterative, incremental development of software. Although agile methods have existed for a number of years now, answers to questions concerning the suitability of agile processes to particular software-development environments are still often based on anecdotal accounts of experiences. An appreciation of the (often unstated) assumptions underlying agile processes can lead to a better understanding of the applicability of agile processes to particular situations. Agile processes are less likely to be applicable in situations in which core assumptions do not hold. This article examines the principles and advocated practices of agile processes to identify underlying assumptions. It also identifies limitations that may arise from these assumptions and outlines how the limitations can be addressed by incorporating other software-development techniques and practices into agile development environments.

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.

An investigation of risk perception and risk propensity on the decision to continue a software development project

Abstract Many information system (IS) failures may result from the inadequate assessment of project risk. To help managers appraise project risk more accurately, IS researchers have developed a variety of risk assessment tools including checklists and surveys. Implicit in this line of research, however, is the assumption that the use of such devices will lead to more accurate risk perceptions that will, in turn, lead to more appropriate decisions regarding project initiation and continuation. Little is known, though, about the factors that influence risk perception or the interrelationships that exist among risk perception, risk propensity, and decisions about whether or not to continue a project. Without a better understanding of these relationships it is difficult to know whether the application of risk instruments will be an effective means for reducing the incidence of IS failure. This study presents the results of a laboratory experiment designed to: (1) examine the relative contribution of two factors that are believed to shape risk perception: probability that a loss will occur and the magnitude of the potential loss, and (2) explore the relative influence of risk perception and risk propensity on the decision of whether or not to continue a software development project. The results indicate that magnitude of potential loss is the more potent factor in shaping risk perception and that a significant relationship exists between risk perception and decision-making. The implications of these findings are discussed along with directions for future research.

Traditional, iterative, and component-based development: A social analysis of software development paradigms

Information systems have always been developed through social processes, wherein actors playing a variety of specialized roles interact to produce new business applications of information technology. As systems development practices continue to evolve, an ongoing assessment of their social implications is required. This paper develops a framework for understanding the potential social implications of an emerging, component-based development paradigm. Like two alternative paradigms for systems development, the traditional life-cycle and the iterative-incremental paradigms, the new component-based paradigm requires that certain generic roles be performed to build a desired application. For each paradigm, we identify the actors who play different roles, specify the nature of their interdependence, and indicate the requirements for managing conflicts constructively. The framework may guide research into the social dynamics of system development and serve as a tentative guide to the management of information systems development.

Towards a Model-Driven Approach to Reuse

A model-driven reuse approach that is based on an organization’s Enterprise Architecture (EA) and on the Unified Modeling Language (UML) is proposed. The framework embodying the approach allows an organization to evolve, from a repository-based to a model-based reuse approach in which reusable experiences are embedded in modeling languages, as an application domain becomes more stable and well-understood over time.

Virtual Linux servers under z/VM: security, performance, and administration issues

In this paper we describe our experience at Colorado State University running hundreds of virtual Linux® servers on an IBM S/390® mainframe with the z/VM® operating system and the way we solved the security, performance, and administration problems that were encountered.

Model-Driven Approaches to Software Development

“Extreme Programming”, “Agile Modeling”, “Model-driven software development”, “Model-driven architectures”, “Agile Development”, “OMG’s MDA”. These catch-phrases are currently the topic of much discussion in the software development world.