Abstract
Introduction: This paper presents and discusses the application of original qualitative and quantitative techniques for evaluating interrelations between factors identified as a priori and determining safety levels for building users in case of a fire, A recurrent numerical process, typical for cognitive map application, is normally used in such an evaluation. The authors suggest an alternative to the classic algorithm, by harnessing the DEMATEL method. The discussed approach appears easier to cope with and allows for a specific analysis of cause and effect relations between factors under consideration. The starting point for this approach is expert opinion applied on a multi-level evaluation scale. The algorithm can be easily adapted to examine uncertain or incomplete information e.g. application of fuzzy numbers [8] [9]. The cognitive process is represented by an impact-relations-map, whose vertices represent comparable factors and arcs reflect direct relationships between factors. Such relationships need not be one directional, they can mirror potential feedback to be incorporated in the analysis. The final evaluation sums up direct influences and the more difficult emerging indirect influences. For easier interpretation of data it is suggested that a threshold value is determined to limit superfluous information and therefore exclude factors with relationships not considered sufficiently intensive to afford clear and unequivocal deductions. The proposed maps are represented mathematically by relative matrices of direct, indirect and total influence. Moreover it is also possible to establish the net total matrix. The idea proposed by the authors is illustrated in this paper with the aid of a simple numerical example, dealing with a single expert opinion, in which the assumed influence structure between proconsidered factors does not include feedback. Furthermore, only one deterministic data set is applied to express levels of direct influence. More advanced and complex examples are presented and discussed by the authors in other papers. Interested readers will find relevant details in the bibliography.
Keywords: fire, safety, cognitive maps, influence map, DEMATEL