A structured methodology to ascertain requirements for computer-based decision support systems

The discrepancy between the needs of decision makers and the information and decision support provided by an organization's computer-based information processing system frequently motivates decision makers to acquire their information and decision support elsewhere. This has a negative impact on decision making processes, in terms of the time and effort expended by decision makers and the assessment of benefits the system provides relative to its costs. The needed information and decision support should be provided by a decision support system, defined here as a computer-based information processing system that directly supports and is used by the organization's decision makers. The resulting savings of time and effort should result in better decision making. This could raise the efficacy of the organization in an environment increasingly characterized by accelerating change and an ever-widening range of choices. The discrepancy between what decision makers need and what is provided by the organization's information processing system results primarily from inadequate conceptualization of the decision task environment by decision makers, system designers, and system implementers. This is partly a result of the inadequacy of conventional computer system design methods to transliterate the largely unverbalized models used by decision makers to solve problems and make decisions. This study showed that actual models used by decision makers to solve problems and make decisions, defined here as models-in-use, are different from their espoused models. Understanding problem solving and decision making models-in-use is the first step in ascertaining decision support requirements. Algorithmic procedure--e.g., a standardized checklist--is unsatisfactory for representing the models-in-use; an interactive response-activated method is required. This research developed a four-step methodology, based on selected constructs of general systems theory, behavioral science, and information technology, to meet the perceived need. The methodology is used by a decision support analyst to dissect decision makers' problem solving and decision making models-in-use and to integrate the findings into a model of the organization as an information processing and decision making system. The model can be used to ascertain specific requirements which then become the basis for designing a decision support system. The methodology was developed in a series of personal interviews with over 50 decision makers in a variety of organizational settings, and in two detailed organizational studies. The methodology was adapted to incorporate empirical findings, and then applied to a third organization, with the results incorporated into development of a decision support system.