10 th HSTAM International Congress on Mechanics, Chania, Crete, Greece, 25 - 27 May 2013 CRISP AND FUZZY ADVANCED HIERARCHY PROCESS FOR THE DESIGN OF AN INDUSTRIAL BUILDING BASED ON TIMBER AND STEEL ELEMENTS Georgios E. Stavroulakis 1 , Dimitrios N. Kaziolas 2 and Theodoros Galanos 1 1 Department of Production Engineering and Management Technical University of Crete Chania, GR-73100, Greece e-mail: gestavr@dpem.tuc.gr; teddian@gmail.com ; web page: http://www.comeco.tuc.gr 2 Technological Educational Institute of Kavala Drama, GR-66100, Greece e-mail: dnkazio@yahoo.gr; web page: http://www.kaziolas.weebly.com Keywords: Analytical Hierarchical Process, Fuzzy AHP; Multi-criteria Desicion Making; Sustainable Development; Structural Design Abstract: Sustainable Development (SD) emerged in the late 90’s, as a response to severe environmental prob- lems worldwide and the public pressure they created. SD introduced the notion of environmental and social con- sequences of anthropogenic activity, affecting the paradigm of ’business as usual’ and increasing the complexity of design and implementation of new, environmentally and socially responsible, strategies. Decision making under these new coordinates has to tackle with both quantitative and qualitative information, as well as the relationship between the two. A combination of different knowledge domains, and the different methodological options they introduce, is necessary for tackling complex problems. This research focuses on this (new) challenge, specifically for the construction sector. Two methods, crisp and fuzzy Analytical Hierarchical Process (AHP), are used for the evaluation of the design of a (generic) industrial building. A decision making process is developed, where a prob- lem hierarchy is created, expert knowledge is gathered and evaluated and final priorities of alternative solutions are produced, through a crisp and a fuzzy handling of data. The case study offers a first exploration, indicating the applicability and easy of use of the methods, presenting preliminary results and proposing further research trajectories. 1 INTRODUCTION The method of Analytical Hierarchical Process (AHP) is used for the solution of difficult multi-criteria optimization and decision making problems. The optimization problem is splitted in simplest one-by-one comparison questions, which in turn can be resolved from one or more experts. This expert information is used for the evaluation of the various alternative solutions to the problem and the hierarchical evaluation of them. Finally the various alternatives are sorted and the solution is presented to the end-user. Adoption of fuzzy variables and fuzzy inference tools allows us extend the previous method to work with fuzzy variables. An academic example is solved with details: the design of an industrial building using steel and timber struc- tural components. Timber and steel structures, due to the reusability of the materials, are best solutions from the environmental acceptability point of view.