Scientific Bulletin of the Electrical Engineering Faculty – 2008 AN OVERVIEW OF THE DSS DEVELOPMENT Ana.Maria SUDUC 1 , Mihai BIZOI 2 Abstract: This paper presents some basic approaches, strategies, methodologies used for developing information systems, in general, and decision support systems, in particular. The classical and iterative designing methods are widely used in information systems development. Each method is generally presented and there are highlighted the advantages and disadvantages of each method in decision systems development. Keywords: decision support systems, development approaches, strategies, methodologies. 1. INTRODUCTION A Decision Support Systems (DSS) are a class of interactive, flexible, and adaptable computer-based information system s, especially developed for supporting the solution of a non-structured or/and semi-structured problems for improved decision- making . It utilizes data, provides an easy-to-use interface, and allows for the decision maker's own insights. In (Filip, [1]) a DSS is viewed as an anthropocentric, adaptive and evolving information system which is meant to implement the functions of a human support team that would otherwise be necessary to help the decision-maker to overcome his/her limits and constraints he/she may encounter when trying to solve complex and complicated decision problems that count Because of the DSS nature, usually it is strongly recommended to include in the DSS developing team, besides the specialists, the potential users. The team members involved in the DSS development must collectively meet a series of requirements (Holsapple and Whinston [2] apud Filip [3]): to know the application field; to widely identify the requests related to the decisional task fulfilling and specific end users requirements; to have or gain access to adequate knowledge sources regarding the decisional problems approaching ways; to know one or more DSS designing methods; to know a widely set of informatics tools which can be used for application system development. The persons involved in the DSS development can meet to certain degrees the above- mentioned requirements. 2. APPROACHES A DSS development involves several principles that must be followed: – to globally approach the problem which must be solved; – to use a unitary methodology for designing and developing the system; – to apply the newest solutions and techniques in information systems designing and developing; – to create the information system relatively independent of the organizational structure of the company where the system will be implemented; – to involve the future system direct beneficiaries in the analysis, design and implement activities of the information system; – to develop the designing activities in accordance with the low and with the user available resources; – to forecast and control the potential software changes; – to document the possible compromises inherent to the software developing; In general, in the information systems development, there are three approaches: top-down approach, bottom-up approach and mixed approach). 2.1. Top-down approach The top-down approach (Wirth [4]), based on the modularity principle, consists of the gradual decomposition of a complex system. This decomposition is implemented from the top to the bottom, to a fundamental modules level. The decomposition follows the functional structure of the system. At the end of the process, the system functional tree is identified and the functional modules and the connections are defined on each hierarchical level, offering a description of each system component. Through this approach, the system gains a modular hierarchical structure. Each component implements a particular functionality. The components are coordinated by the components placed on the immediate upper neighbor level. This approach is applicable to the complex wide range information systems. When a system functional module is made, it can be set into service. Afterwards, the other future developed modules will be integrated into the system. The integration should not cause problems due to the unitary strategy system design. The top-down approach involves a special effort in the analysis phase (a complex and very detailed analysis 1 Valahia University Targoviste, Electrical Engineering Faculty, Systems Science, Automation and Informatics Department, mihaibizoi@yahoo.com 2 Valahia University Targoviste, Electrical Engineering Faculty, Systems Science, Automation and Informatics Department, e-mail: anasuduc@yahoo.com 99