A Methodology for Estimate Safety Barriers Effectiveness on Construction Industry Incorporating Uncertainties by the Use of Fuzzy Sets

In occupational safety, prevention and protection usually involve the use of some sort of barriers. To estimate accurately safety barriers effectiveness it is of paramount importance to assure its performance and consequently keep the risks on adequate levels. But, what is safety barrier effectiveness? How to estimate it without statistical reliable data? Estimate the effectiveness of safety barriers is a complex process that entails the consideration some quantitative parameters as well as perceptions which are fuzzy by nature and its assessment process involves complexity and uncertainty. A fuzzy approach is a better mathematical framework to estimate safety climate because uncertainty represented on fuzzy systems is a non-statistical uncertainty, which express vagueness, imprecision and/or ambiguity through fuzzy membership functions, and has a different nature from statistical uncertainty that is based on the laws of probability and is resolved through observations. Departing from a literature review on safety climate, a set of factors affecting safety climate on construction sites were identified. A pole of six Portuguese construction safety experts contributed to adapt these factors to the Portuguese construction sites reality. The model was tested, conducting real case studies, by “peer” reviews by a pool of 11 safety experts from Brezil (2), Greece (3), Portugal (2), Turkey (3) and Bulgaria (1). Estimate safety barriers effectiveness is of particular value to avoid the occurrence of work accidents that are costly in terms of the potential for loss of equipment, material, man-hours and human lives. The assessment tool developed and presented in this work seems suitable and easy to use by safety practitioners in construction sites. Hence, in this work our objectives are: (1) to present a survey about concepts and performance of SB, (2) to overview how SB are used in construction industry and, (3) to provide a practical tool for assessing safety barriers effectiveness, using a fuzzy sets theory approach.