## 1 Introduction
However, multibody systems significantly distort magnetic fields and a single broken wire may remain undetected. Recently, a method and device appeared that utilizes the remaining magnetic field in ferromagnetic materials (RMF), and has advantages against other magnetic methods in accuracy and convenience due to the compact and light nature of the device. Practical implementation of RMF confirms its usefulness in defect-finding and small friction value between sensor tip with testing the rope surface [13; 24; 25]. The presented papers deliver extensive results into the research of rope diagnostics and fault finding. On the other hand, research on the rope quality dependence from amount of broken wires in the rope is still missing. The detection of broken wires on the rope surface is performed using optical inspection, therefore, implementation of new methods and devices is requested [2; 3; 4; 5]. With data obtained from sensors after signal processing, there are rare cases when the signal offers a clear case of damage. The definition of damage with high possibility is given by the multi-criteria decision-making (MCDM) methods, which takes into account the general dataset from the hardware and derives a solution after objective data analysis. In MCDM methods, definition of criteria weights is an important stage. In the practical implementation of MCDM methods, criteria weights are defined be experts. In our case, subjective evaluation of the criteria weights is not applicable, because experts have difficulty in defining criteria weights. Therefore, it is possible to define criteria weights using objective criteria weight definition methods. These weights are used in the MCDM methods to define the best alternative or aligning alternatives according to importance. In technical diagnostics, the implementation of decision-making procedures has a great potential. In many real cases, there exists a need to evaluate a situation described by more than one criteria, therefore MCDM methods are used. These methods become especially useful for research of sustainability and reliability, when few criteria of efficiency are evaluated at the same time. Implementation of MCDM methods in the field of engineering can be illustrated by comprehensive research of steel structures, steel bridges (method of Analytical Hierarchy Process (AHP)) [26], and cold-formed Hun-walled steel structures [27]. Extensive implementation of The Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) methods in steel buildings [28] gained success and was extended to wider technological area. Welding processes are evaluated using MCDM with fuzzy logic [29], while laser cutting technological parameters are defined using AHP-TOPSIS [30]. There are many methods for thin-walled structure evaluation using Complex Proportional Assessment (COPRAS) [31; 32; 33; 34; 35; 36; 37], which confirms the implementation of these methods in the field of engineering. The modified method of AHP-COPRAS-G was successfully used for cold-formed steel structure design [38], where the strict physical conditions of material creates high nonlinearities of the mathematical formulation. Non-uniform task for cutting tool material selection [39] and structural materials selection [40; 41; 42; 43] also finely fit into the area of MCDM. Proper selection of machine tools for changing production flow has been performed using fuzzy AHP and COPRAS methods [44]. The aim of this paper is to perform diagnostics of wire rope by finding broken wires using dynamic methods and process the obtained results with multi-criteria analysis. Analysis of the broken wire amplitude from its length and applied vibration frequency remains an important issue. Data, obtained from extensive diagnostics process, require special processing, which will reveal the true defect with a possibly high chance.