Aleksandar Brkić

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.

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.