Asset management, as a systematic process of operating, maintaining, and upgrading physical assets, is an important element of decision-making in heavy equipment management and operation. Maintenance strategy selection plays a significant role in mining design. However, the nature of maintenance strategy selection is a complex multi-criteria decision making (MCDM) problem including both tangible and intangible parameters which are often in conflicting with each other. As well as when decision makers are uncertain in determining and defining the ratings and the weights of alternatives and criteria respectively, fuzzy theory provides an appropriate tool to handle the existing uncertainties. In this paper, a new fuzzy MCDM method based on the concepts of COPRAS (COmplex PRoportional ASsessment) and AHP (Analytical Hierarchy Process) was proposed to evaluate the feasible maintenance strategy. The linguistic terms are employed to assess the ratings and weights. Fuzzy AHP is utilized to calculate the weights of the evaluation criteria; then, the rankings of alternatives are computed based on fuzzy sets theory and COPRAS. A real world case study is presented to illustrate a potential application of the proposed model. Santrauka Turto valdymas, kaip sistemingas veiklos procesas materialiajam turtui palaikyti ir atnaujinti, yra svarbus sprendimų priėmimo sandas, reikalingas sunkiajai įrangai valdyti ir naudoti. Pasirinkti priežiūros strategiją yra ypač svarbu projektuojant kasybą. Tačiau techninės priežiūros strategijos parinkimo pobūdis yra sudėtingas daugiatikslio sprendimų priėmimo (MCDM) uždavinys, apimantis tiek materialius, tiek nematerialius aspektus, tarpusavyje dažnai prieštaraujančius. Kai sprendimų priėmėjui kyla neaiškumų nustatant ir apibrėžiant rodiklių vertes ir svorius, neraiškiųjų aibių teorija yra tinkama priemonė esamam neapibrėžtumui aprašyti. Straipsnyje pateikiamas naujas neraiškusis MCDM būdas, pagrįstas COPRAS (kompleksinio proporcingo projektų įvertinimo) ir AHP (analitinio hierarchijų proceso) metodais, tikslingoms nekilnojamojo turto palaikymo strategijoms įvertinti. Rodiklių vertės ir svoriai yra apibrėžti lingvistinėmis sąvokomis. Neraiškusis AHP taikomas vertinimo rodiklių svoriams apskaičiuoti. Paskui alternatyvų rangai nustatyti taikant neraiškiųjų aibių teoriją ir COPRAS metodą. Naujai pasiūlytas modelis pritaikytas realiam uždaviniui spręsti.

Loading and hauling contribute significantly towards expenses in surface mines. Thus selecting the most suitable system which minimizes the cost per ton and meets production needs is one of the main concerns of mine design and planning. It is also at times difficult to select the optimum equipment, as there are many possible options and influencing factors in selecting a system. Furthermore, some of these factors can be either quantitative or qualitative. As a result, the use of multi attribute decision making methods can be useful. In this article, the selection of the equipment fleet of Gole Gohar mine was done though four stages. First, feasible technical and operational options were determined. Next, the weights of influential criteria were determined using a hybrid method of fuzzy analytical hierarchical process and analytical network process. Then, the alternative preference rating matrix was calculated using fuzzy TOPSIS method and finally, the hierarchy of alternatives was decided by combining the available weight and ranking matrix. This model considers all affecting parameters simultaneously and facilitates making a reasonable decision about the most appropriate material handling equipment. For the purpose of evaluation in this method, the cost of each equipment fleet was assessed and compared using the traditional method. Results show that the use of the fleet of cable shovel and truck is the most economical loading and hauling system. The results not only indicate that proposed model offers chances to choose the best alternative among possible loading and hauling systems, but also help equipment managers to make an accurate and reasonable decision regarding all effective parameters.

Shafts have critical importance in deep mines and underground constructions. There are several traditional and mechanized methods for shaft sinking operations. Using mechanized excavation technique is an applicable alternative to improve project performance, although impose a huge capital cost. There are a number of key parameters for this selection which often are in conflict with each other and decision maker should seek a balance between these parameters. Therefore, shaft sinking method selection is a multi criteria decision making problem. This paper intends to use the combination of analytical hierarchy process and TOPSIS (Technique for Order Performance by Similarity to Ideal Solution) methods under fuzzy environment in order to select a proper shaft sinking method. A real world application is conducted to illustrate the utilization of the model for the shaft sinking problem in Parvadeh Coal Mine. The results show that using raise boring machine is selected as the most appropriate shaft sinking method for this mine. Santrauka Gręžiniai yra labai svarbūs giliose šachtose ir požeminėse konstrukcijose. Gręžiniai įrengiami keliais tradiciniais ir mechanizuotais metodais. Mechanizuotos žemės kasimo technologijos yra galima alternatyva, gerinanti projekto įgyvendinimą, tačiau tam reikia didžiulių kapitalo išlaidų. Pasirinkimui įtaką daro daug tarpusavyje nederančių rodiklių, tad sprendimą priimantis asmuo turi rasti balansą tarp jų. Todėl grųžiniu įrengimo metodo parinkimas yra daugiakriterinių sprendimų priėmimo problemą. Šiame straipsnyje naudojama analitinio hierarchinio proceso ir TOPSIS (artumo idealiajam taškui) metodo neraiškioje aplinkoje kombinacija tinkamam gręžinių įrengimo metodui parinkti. Modelio naudojimo atvejis iliustruojamas realiu pavyzdžiu, sprendžiant gręžinių irengimo problemą Parvadeh anglių kasykloje. Rezultatai rodo, kad keliamasis gręžimo įrenginys parenkamas kaip tinkamiausias gręžiniams įrengti šioje kasykloje.