Vesna Spasojević Brkić

Employees factors importance in Lean Six Sigma concept

Purpose – Lean management and Six Sigma concepts are derived from two different points of view, but it is evident that the role of employees is crucial in both concepts. The purpose of this paper is to survey which employees’ behaviour dimensions can lead organization to better concepts integration and how Lean Six Sigma activity contributes to employees’ performance. Design/methodology/approach – Research methodology is designed to empirically check, on large sample of companies in multinational company supply chain, if employees’ factors are both predictor and response variables of Lean Six Sigma concept. To check stated hypothesis factor, reliability and multiple regression analysis are used. Findings – The first finding of this study is that reward system and training are significant predictors of Lean Six Sigma activities. The second part of findings shows that Lean Six Sigma dimensions, such as Define, Measure, Analyze, Improve, and Control/Define, Measure, Analyze, Design, and Validate, 5S and Kanb...

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.

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.

Identifying and Categorizing Risks of New Product Development in a Small Technology-Driven Company

New product development (NPD), as a locus of the innovative potential of organizations, plays an essential role in small technology-driven company survival. To address the research gap and fulfill the companies’ needs, this survey aims to post and verify a new, simple and not time-consuming methodology for risk identification and categorization of industrial products development. To check the hypothesis that NPD project technical, cost and schedule sets of risks could be categorized as both threats and opportunities, an experiment was conducted in a small Serbian enterprise that has developed 52 innovative solid state based lighting products for outdoor lighting infrastructure. There were 69 identified risks (51 threats and 18 opportunities) that through 76 factors influence new products’ technical characteristics, schedule and cost. Explorative factor analysis was applied to reduce and compress the data and 26 composite factors were obtained as valid predictors of the NPD project results. Regarding the technical characteristics risks, the threats can be grouped into four factors consisting of six risk types, while opportunities can be grouped into two factors consisting of four risk categories. The risks influencing the schedule disturbance that act as threats are grouped into eight factors consisting of ten risk types, while those that could be used in opportunities are grouped in four factors with eight risks identified. The risks influencing the costs that threaten the project are recognized as five factors described by seven risks, while those that act as opportunities are grouped into three factors described by five variables in total.

Serbian and Libyan Female Drivers’ Anthropometric Measurements in the Light of the Third Autonomy Level Vehicles

At level 3 the driver still remains “in-the-loop” due to the inability of the automated system to manage a particular driving situation/environment and anthropometric data are still essential in design. In that aim anthropometric measurements of 193 Serbian and 50 Libyan female drivers have been collected using standard anthropometric instruments and compared using statistical methods - descriptive statistics with Kolmogorov test for normality, linear regression and correlation analysis and comparison of measured anthropometrics using z test. Results obtained in this study are useful to passenger car designers aimed to compete on autonomy level 3 and show that there exist significant differences between Serbian and Libyan female drivers. Future research on other rarely available anthropometric data for other nationalities is recommended, due to globalization trends and constant migrations.

Welded joints as critical regions in pressure vessels – case study of vinyl-chloride monomer storage tank

Welded joints are analysed as critical regions in a pressure vessel in respect to structural failure due to the elastic-plastic fracture/crack growth. To assess structural integrity of pressure vessels used in chemical industry the risk based procedure has been introduced and applied in the case of a large spherical pressure vessel used as a vinyl-chloride monomer (VCM) storage tank in HIP Azotara Pancevo. The risk matrix has been used, taking into account the basic definition of risk, being the product of the probability and consequence, and applied to different regions of welded joints, having different mechanical properties, i.e. crack resistance. To estimate probability, the failure assessment diagram (FAD) has been used, as an engineering tool, defined according to the position of the operating point for different regions of the welded joint, relative to the critical point on the limit curve. Generally speaking, consequence is estimated based on pressure vessel parameters, or by detailed analysis of health, safety, business and security issues, but in the analysed case, the worst case scenario is assumed, with the highest consequence due to potential disaster for environment and fatalities.

Organizational culture, quality improvement tools and methodologies, and business performance of a supply chain

Unlike previous studies that have revealed a link between quality improvement programs and organizational culture typologies in individual companies, this study describes organizational culture dimensions that affect the use of quality improvement tools and methodologies and how both affect supply chain company performance. Structural equation modeling methods are applied to a sample of 200 organizations in the supply chain of a Canadian multinational company. The results show that employee promotion and investment constitutes the most influential cultural dimension. Organizational objectives and an employee reward system individually affect Kaizen. When the level of formalization in an organization is high, Kaizen and total quality management tools are used more intensively. When the level of formalization is low, lean manufacturing and internal audits are used more intensively. Superior communication in an organization causes plan–do–check–act approaches, lean manufacturing methods, corrective actions and internal audits to be used less intensively. Generally speaking, most quality improvement tools and methodologies positively influence business performance. These results suggest that organizations can improve business performance levels by selecting appropriate quality improvement programs depending on existing organizational culture dimensions and may thereby develop an organizational culture that enables successful quality improvements in a supply chain context.

Interfaces for Distributed Remote User Controlled Manufacturing as Collaborative Environment

Recent advances in information and communication technologies that support the concept of collaborative networks have allowed manufacturing enterprises to use remotely controlled decentralized manufacturing processes. This survey is based on the experiment that involved 34 small collaborative groups at Serbia, that have used the interface for remote collaborative control of manufacturing systems to control of CNC machine located in Portugal. The experiments on collaborative environment are done using two types of “client” user interface, “Wall” and “Window”. Measured characteristics included: collaborative effort, involvement, awareness, representational fidelity features and co-presence. Results show that “Wall” interface has higher values of index of interdependence of collaborative virtual environment characteristics. Conclusion is that characteristics of collaborative environment are less interdependent when “Window” is used opposite to the “Wall” interface. Future research ideas are to test similar platforms with more users and to study aspects such as group leader choice and role, possible conflicts etc.

Group Characteristics and Task Accuracy in Distributed Remote User Controlled Manufacturing as Collaborative Environment

Collaborative environments today are very successful when used in multiplayer games and for meetings organizing, which gives an idea to explore its potentials in remotely controlled decentralized manufacturing. This survey is based on the experiment that involved 34 small collaborative groups including 68 students in Serbia, that have used the interface for remote collaborative control of manufacturing systems to control of CNC machine located in Portugal. Our previous surveys have shown that group work consumes less time than individual work in most working options. This paper examines influence of homogeneity of the groups. Results of statistical examination show that percentages of errors are significantly or highly significantly higher in homogeneous compared to a non-homogeneous groups. Therefore, it could be recommended to form heterogeneous groups when remotely controlling decentralized manufacturing processes.