Milivoj Klarin

An empirical examination of the impact of quality tools application on business performance: Evidence from Serbia

This study empirically examines the impact of quality tools on business performance in a sample of 119 Serbian industrial firms. Quality tools are classified into three primary groups according to their usage pattern by means of factor analysis and reliability testing: quality tools for reviewing current conditions, for analysing current conditions and for production planning and control. The relationships between these groups of quality tools and business performance measures were tested using stepwise regression analysis. Quality tools for reviewing current conditions have a significantly positive impact on most business performance dimensions, which is to be expected due to the fact that Serbia is in the phase between quality assurance and total quality management. Quality tools for analysing current conditions significantly influence productivity, while those for improvement have a positive effect on capacity expansion as a development performance measure.

The shift level of the utilization of capacity as the stochastic variable in work sampling

This paper aims to explain and justify the necessity and the importance of using the shift level of the utilization of capacity as the stochastic variable in determining the total level of the capacity utilization in the production process by using the method of work sampling. The aim of the paper is realized through experimental research on the work sample containing 74 Serbian companies. The conclusion is that the shift level of capacity utilization as the stochastic variable in work sampling is the model that solves the problem of determining the total level of capacity utilization in a convenient way with accurate results.

Additional adjustment of the driver seat in accordance with the latest anthropometric measurements of drivers in Belgrade

Abstract This paper presents a sequel to research by two of the present authors published in 1998. In conditions of increasingly tough competition in the market, there is an increasing need to adjust automobiles to anthropomeasures. For the Yugoslav population the construction dimension of automobiles from floor to roof should be at least 1250 mm. Additional adjustment to meet the latest anthropomeasures of drivers should make it possible for the seat to slide backwards by up to 300 mm and to be linearly lowered by 131 mm (with an angle of 23.6° for the seats complete shifting without backrest or the seats seating part inclination change).

Anthropometric assessment of crane cabins and recommendations for design: A case study

BACKGROUND Work of crane operators is very difficult and demanding. Therefore, it is very important that the cabin of a crane be designed on the basis of relevant anthropometric data. However, it is very difficult to find a research that considers anthropometric convenience of crane cabins. OBJECTIVE From the theoretical viewpoint, it is important to perceive and to classify effects of the anthropometric incompatibility of crane cabins. Globally, the objective is to consider the anthropometric convenience of existing crane cabins, and possibilities for improvements of their design from the ergonomic point of view. In this regard, it is significant to detect constraints that impede or hinder the work of the crane operators, which could be overcome with certain anthropometric solutions. The main objective is to examine whether and to what extent is justifiable to use anthropometric data that are obtained on the basis of general (national) population, during designing the crane cabins. METHODS For the assessment of existing crane cabins and the work of operators, four methods were used: observation of the work of the operators and design solutions of the cabins, the checklist approach, interviewing of operators and the experimental research based on obtaining the data on the population of crane operators. RESULTS Results of the analysis based on the method of observation, analysis based on the application of the checklist, as well as interviewing of the operators indicate that certain construction constraints of the components in the cabins are the main reasons of reduced visibility and improper working postures of operators. All this has caused the emergence of continuous musculoskeletal loading of the crane operators. The results of the anthropometric research that were obtained on the population of crane operators in this case study suggest that there is a statistically significant difference, when compared data of this population of workers with anthropometric data from the general population. CONCLUSIONS Analyzed workplaces in crane cabins do not correspond to the majority of operators from the anthropometric standpoint. The conducted anthropometric analysis has been indicated that could be made the mistake, if dimensions of the cabin and layout of equipment would be relied on data derived from the general population of citizens. In order to achieve greater precision in the design and configuration of equipment, it is recommended using the data that are obtained directly on the population of the crane operators when designing the cabin.

Determining the Width of the Optimal Space Needed to Accommodate the Drivers of Passenger Vehicles Using the Analogy of Anthropometric Measurement Dynamics and Mechanical Mechanisms

This paper discusses a new way of modelling the width of the space that accommodates the drivers of passenger vehicles. The fact that there is a more or less fixed zero point, which is the origin of the coordinates of the man-vehicle system makes it possible to determine the mechanical–mathematical co-dependence in this system more accurately. The space is determined by taking extreme pairs of the dimensions and a series of anthropometric measurements to which the vehicle needs to be adjusted as the measurement limits. These were determined by analysis which includes both the theory of mechanisms and vehicle mechanics. In this way the method of adapting the vehicle to accommodate a range from the 5th-percentile woman to the 95th-percentile man has finally been surpassed. The paper demonstrates a methodology for designing the interior space of a passenger vehicle based on the fact that, in a range of anthropometric measurements of equal total lengths, each measurement has segments of different lengths, because people with the same leg lengths have different upper-and lower-leg lengths. Therefore the interior space of the vehicle is designed to accommodate extreme measurements and to allow for limitations caused by movement and the physical laws derived from seeing the anthropometric measurement mechanism as a mechanical mechanism. The paper offers a design for the space behind the windscreen, the position of the steering wheel, and the position of the foot controls together with the total space which the driver occupies, primarily from the aspect of anthropometric limitations, concluding that the maximum width for accommodation of the driver at the lowest level of a seat along the x axis is 169 mm, and along the y axis is 1013 mm.

Determination of passenger car interior space for foot controls accommodation

Abstract This study shows that the automobile is still not well enough adapted for human beings, especially in the part of the interior where the foot controls are located. When designing passenger vehicles ergonomically, the anthropometric limitations are as important as the technical limitations. Moreover, exacting contemporary economic and ecological requirements mean that the interior of the standard passenger vehicle must be designed to reduce front surface and air resistance to a minimum. The present authors offer a new method for designing the part of the interior of standard passenger vehicles where the foot controls are located as an indivisible part of the whole interior, with interrelated functional links using anthropometric limitations. These vary according to region and country and change with time. This study uses anthropometric data for drivers from Serbia from 1976 to 2007. The objective was, taking into account vehicle interior height limitations, to accommodate the largest range of anthropometric dimensions, from the fifth-percentile woman to the 95th-percentile man, which was accomplished using a new method for model accommodation optimization. Furthermore, comfort and a safe steering position are assured. The existence of the O point is required as the origin of a coordinate system with x, y, and z axes for the man—vehicle system and this enables the mechanical and mathematical functions to be defined more accurately within the system. By applying the suggested method and processing the data acquired, an optimum space for foot controls was obtained. The space for foot control location lies horizontally along the x axis forward from the O point by 320mm and vertically along the z axis by 230mm. The space height along the z axis is 465mm. The space is determined in four segments by the anthropomeasures of the foot of the 95th-percentile man and the fifth-percentile woman, first starting from the floor line to the point (−320mm, 230mm). Also, it is determined by the height of 465mm of the 95th-percentile man to the point (50mm, 465mm), when the space as far as the lower half of the windshield glass is defined by the fifth-percentile woman. In this way, a larger space is needed for seating of the fifth-percentile woman than would be needed if only the 95th-percentile man were seated.

Multi-criteria approach to optimization of enterprise production programme

This paper develops a multi-criteria model for making decisions on the production programme relevant for industrial enterprises. It presents some possibilities of using the method of multi-criteria decision making with managerial decision making on the production programme and some possibilities of modelling and disclosing preferences of a decision maker when conducting multi-criteria rating of alternative solutions by applying the concept of PROMETHEE method. The development of a multi-criteria basis for multi-layered and multi-level decision making in a system of relevant criteria, including development aspect, technical and technological aspect, economic aspect, competitive aspect, and humanity aspect, with a set of relevant criteria indicators of quantitative and qualitative nature. By introducing new types of preference functions and by applying them to the multi-criteria decision making of the production programme and to the software support implemented there, original solutions to the problem of the programme orientation optimization are offered. Practical testing of the projected model and of the complex procedure of multi-criteria decision making was demonstrated in practice with the example of a multi-criteria approach to the selection of an optimal variant for the programme of hail suppression rockets production. A multi-criteria approach ensures finding solutions for, and examining the products that are a key to, the long-term development of the enterprise.

Stohastic Model to Determine the Elements of the Production Cycle Time: Case of Serbian Textile Industry

The paper presents an original method of determining the elements of the production cycle time by using the modified work sampling method applied to a textile factory. It is shown that the movement of the elements of time can be viewed as a process and in the mathematical sense can establish control limits of error of ± 3 SD. The mean time of the production cycle of the groups created by the number of pieces in the series – tpcu moving the hyperbolic function, which has the asymptote c, a function of the form tpcu = c + b/log n, where all groups of the production cycle in the mathematical sense do not act like strata but are function tpcu related to technology and deterministic factors of the production series.

Reduction of production cycle time by optimising production and non-production components of time in the metalworking industry : a case study

The production cycle (PC) time, as a very important economic indicator of freezing current assets, involves the time needed to manufacture a unit or a series of units, from putting them into production until they are put into storage; and yet it is rarely discussed in the literature, even though it should be also analysed and be made as short as possible. The goal of this article is to survey and control the methodology of reducing the PC time of components in the metalworking industry, grouped by factor analysis into the factors of production and non-production components, observed by a modified method of current observations, and viewed as a process whose effectiveness was monitored using control charts. The survey is based on data collected through 1,576 observations in a Serbian company that manufactures electrical and electronic equipment for motor vehicles. The 2012 results, when compared with those of 2011, indicate that the PC time is significantly reduced by 93 minutes, or by 28.53 per cent, and the manufacturing time by 46 minutes, or by 19.17 per cent. The results furnish empirical findings that provide insights into a number of managerial issues concerning investment decisions in product-specific cycle time improvements and reductions, together with process redesigns.

Effectiveness of quality management factors and differences in total factor productivity

Quality management (QM) programme often is not a measure of high organisational effectiveness and business performances, so it is of interest to explore the relation between QM critical factors and total factor productivity (TFP). In this study the data were collected in the period 2004-2009 from Serbian industrial firms certified according to ISO 9000 with a total number of 176 observations. In order to determine the total factor productivity through the production function variables describing the dependence of added value and labour and capital factors of production were used. For the QM data, the results underwent factor analysis and reliability calculations so as to be used as independent variables in multiple regressions. The key result of this study is the confirmation of the hypothesis, that firms having above average score for a certain QM factor register statistically significant positive and negative differences in TFP, against average productivity of all firms in the sample.