A content analysis in reverse logistics: a review

The purpose of this paper is to provide a comprehensive review in the various publications on the concept of Reverse Logistics (RL) and the related areas within the period 1998-2012. The content analysis approach has been opted to collect the relevant information from different books, journals, and conferences. A broad review of literature in RL from its emergence until the recent discussions have been analyzed and compared in this research. The findings show that, the theoretical construct in RL has been initiated from the conjunction features in the waste management and logistics activities. This idea had been developed by introducing the new term as RL and its definitions and contents such as the activities; key drivers; barriers to use; material flow, and networks in RL. Furthermore, the findings present the various modelling in different aspects of RL, for instance, the mathematical modelling by applying the existence methods in Multi Attribute Decision-Making Models (MADM). In addition, the environmental concerns and governmental legislatives matters and impacts, which have been highlighted, recently, on RL have been deliberated. Hence, this paper would assist the researchers and practitioners to obtain a broad review of RL in the last decade and, also provide an agenda for the future researches

Complex evaluation of contracts for construction

The effectiveness of construction processes largely depends on the effective contract preparation. To draw an effective contract for construction, the methods of assessment and comparison of these types of contract should be developed. In recent years, multicriteria methods have been widely used for evaluating various complex phenomena. The development of construction evaluation methods requires the analysis of construction technology and organization, as well as economic factors and legal aspects of contracting in construction. In the present investigation, the criteria describing contracts for construction from various perspectives are determined based on the estimates elicited from experts. The weights of nine criteria used in complex evaluation of construction contracts are determined based on the use of the AHP method. The consistency of expert estimates is also assessed. Using multicriteria evaluation methods, construction contracts are compared and the best alternative is determined. Santrauka Didele reikšme statybos proceso efektyvumui turi tinkamas statybos rangos sutarties sudarymas. Siekiant sudaryti efektyvias statybos rangos sutartis, reikia sukurti rangos sutarčiu ivertinimo ir palyginimo metodikas. Pastaruoju metu sudetingiems procesams vertinti plačiai taikomi daugiakriteriniai vertinimo metodai. Ju vertinimas priklauso nuo rodikliu, charakterizuojančiu procesa, ir ju reikšmingumo. Siekiant parengti statybos vertinimo metodikas, reikia išnagrineti ne tik techninius, organizacinius, ekonominius, bet ir teisinius statybos rangos sutarties aspektus. Taikant ekspertu vertinimus, buvo nustatyti rodikliai, charakterizuojantys statybos rangos sutarties turini. Kompleksiškai ivertinant statybos rangos sutartis AHP metodu nustatyti devyniu rodikliu svoriai, ivertintas ekspertu nuomoniu suderinamumas. Taikant daugia‐kriterinius metodus tarpusavyje palygintos statybos rangos sutartys ir nustatytas geriausias variantas. First Published Online: 24 Jun 2011 Reikšminiai žodžiai: statybos ranga, daugiakriterinis vertinimas, rodiklis, AHP metodas, ekspertu vertinimas, suderinamuma

A method of determining risk zones of investment in real estate

In the real estate sector, especially in construction or purchasing of commercial buildings, adequate evaluation of market development and property management is of paramount importance. In this paper, application of mathematical modelling to evaluating the efficiency and risk of investment projects is discussed. Most of the microeconomic models are discrete, implying that the initial data and the results obtained are discrete values. In the suggested model, the most likely variability intervals of the parameters are taken as the basis of modelling. The models suggested in the present paper deal with local investment problems, which should be promptly solved in the presence of a great number of alternative investment possibilities. The modelling is aimed at determining zones related to the quality of decisions in the area of investment. The principles of mathematical modelling and determination of various financial risk zones are described. An example of determination of risk zones of investments in Vilnius are presented

Application of a quantitative multiple criteria decision making (MCDM-1) approach to the analysis of investments in construction

The paper considers major principles of methods based on quantitative measurements. The problem of construction investments is of paramount importance because they determine the potential of construction and the structure of expenses. The calculation of investments is an expensive tool of enterprise management used in planning the investments. It can be perceived as the harmonization and evaluation of the models for investment decision-making. Methods based on a single criterion can hardly be used in solving the problems associated with sophisticated technological or marketing systems. It is a multiple attribute decision method, taking into consideration major efficiency criteria, that enables the effective methods of solving complicated problems. When the quantitative criteria are precisely defined, the developed quantitative multiple criteria decision making (MCDM-1) method can be successfully applied. The present paper is devoted to the analysis of the algorithm and methods of application of the suggested technique

MULTICRITERIA EVALUATION OF COMMERCIAL INDUSTRIAL ZONE DEVELOPMENT

The article presents the results of the analysis of Vilnius district commercial-industrial zones. The criteria of analysis are: geographic location, plots and/or groups of plots in the area, operating and planning activities of companies as well as the infrastructure and transport communications development at the engineering level. A theoretical model for investment strategy selection is introduced to identify the possibilities of investment attractiveness. The principle of the investment option with the system of characterizing indicators for development is offered to reflect the lack of cohesion between practical investment promotion and sustainable development of the territories’ indicators

Surface based cohesive behavior implementation for the strength analysis of glued-in threaded rods in Glulam

The paper presents the analysis of strength and stiffness of metric threaded steel rods glued in glulam obtained by using two different gluing methods. The first method is used when the threaded steel rod is glued into a groove larger than the rod’s diameter, while the second method is applied when the diameter of the groove is smaller than the diameter of the threaded steel rod. The steel rod is covered with glue before it is inserted into the smaller diameter groove. The first method investigates the 2-mm-thick glue-line, while the second method analyses the contact when the groove’s diameter is 2 mm smaller than the outer diameter of the rod. Epoxy-type resin is used for both gluing methods. Different gluing methods present different interactions between the steel rod and glulam which result in different failure modes. The second method presents a plastic failure between the steel rod and glulam caused by the local compression and shear of glulam. The presented studies are made using metric threaded steel rods of diameters M12 and M16. In total, 20 specimens are experimentally tested in tension-to-tension tests performed according to EN 26891. The interaction between glulam and glued steel rods is also investigated using the 3D finite element modelling. The results obtained using the proposed 3D finite element model with different contact conditions between steel and glulam and the failure criterion for timber shear are well in line with the experimental findings

COMPUTER-AIDED DECISION-MAKING IN CONSTRUCTION PROJECT DEVELOPMENT

One of the most difficult problems in construction is taking objective decisions. A decision-making process is very complicated and time consuming (due to the complex nature of construction projects). Many experts with extensive knowledge of construction industry take subjective decisions related to verbal methods of decision-making. Difficulties are related mostly to the creation of a set of relevant criteria, providing answers to the decision-maker’s questions. A set of proper criteria and mathematical tools (such as computer calculation algorithms with multi-criteria analysis) could significantly improve objective decision-making. The paper presents ESORD – an informatics tool allowing to establish a hierarchy (ranking) of different types of solutions on the basis of mathematical calculation. The authors present a comparison of different methods used for multi-criteria decision-making