Michał Rogalewicz

Statistical Approach to Making Decisions in Manufacturing Process of Floorboard

The study was conducted at a Polish company operating in the wood industry under the R&D project “Increasing the effectiveness of use of wood in manufacturing processes”, aimed at reducing raw material waste in the surface layer manufacturing process. Results of our studies on the improvement of the wet cutting technology are presented in this paper. Minimization of variability is the first step to reduce material consumption in the process of cutting wood into lamellas. Appropriate values of factors which significantly affect lamella thickness after the cutting operation can be determined through real-life experiments. The methodology is to improve and/or reduce operational allowances and to redesign the tolerance and machine parameters/setting.

Soft Modelling-Based Methodology of Raw Material Waste Estimation

The paper looks at soft modelling-based estimation of raw material waste for various variants of a technological process under development. A methodology of assessment of new technology variants, in terms of minimization of the input material waste, is presented. Results of an analysis of variants of a new technology of manufacturing of the middle layer of a flooring board, carried out according to the developed methodology, are shown. The assessment is performed in an original software tool for waste simulation. It is shown that the developed methodology supports the estimation of material waste and assists in the selection of the optimal variant of the process, taking into consideration the constraints of the organization.

Organization of Visual Inspection and Its Impact on the Effectiveness of Inspection

The research presented in this paper was aimed to analyse and evaluate the impact of organizational factors on the effectiveness of visual inspection in the manufacturing of electronic systems for the automotive industry. The study was carried out according to the authors’ own methodology consisting of three stages: detailed description of the process, developing a study plan and analysis of the results. The experiment was conducted and influence of three factors: type of inspection, shift and type of defect, was taken into consideration and evaluated. Recommendations were made to improve the quality of such inspections that will lead to the improvement in the final quality of the product.

Methodology Supporting the Planning of Machining Allowances in the Wood Industry

The paper presents a methodology of determination of technological allowances in the manufacturing process of semi-products of deciduous timber (oak). Soft modelling has been proposed for the determination of allowances for the variability of consecutive technological processes caused by the material, machine, operator, measurement system and random factors. The proposed methodology has been applied in the technological process of manufacturing the surface layer of a floor board (lamella). The method of identification of a soft model for the process of cutting timber into lamellas has been presented. Twenty soft models have been identified and recommendations have been made, based on experiments, for reducing the variability and centering the process. The proposed process modelling method facilitates economic estimation of allowances, controlling the manufacturing process and forecasting its future condition. As a result of the research, the manufacturing capacity of lamellas of acceptable quality has been increased by ca. 30%.

Artificial Neural Networks as a Means for Making Process Control Charts User Friendly

The paper discusses usability of various pattern recognition methods, especially based on artificial neural networks for decision making support in process control chart analysis. Their effectiveness for detecting process instability is compared with the effectiveness of a human operator and of a widely accessed commercial statistical software. The results are verified on the basis of data obtained from real production processes.

Automatic Assist in Estimating the Production Capacity of Final Machining for Cast Iron Machine Parts

The paper presents a new approach for production capacities balancing. It is dedicated to companies performing machining services on a variety of materials on a small scale. The method is to help balance the production capacity on the basis of a defined labor intensity structure taking into account the share of set-up times and the level of defectiveness. The designed numerical algorithms along with the user interface make it possible to characterize machine tools and orders in the production system and compare the production capabilities of the system with the demand. The paper presents the algorithm working pattern, mathematical formulae used and a sample source code. An example of a computer application allowing to estimate the production capacity for sample orders (cast iron castings) and process routes in a selected cast iron production plant are also presented.

Application of Cluster Analysis in Making Decision About Purchase of Additional Materials for Welding Process

The concept of Industry 4.0 requires a computerized manufacturing environment which permits to increase flexibility of processes, faster communication and integration of various areas of business operation. It also involves collecting and processing a lot of information in databases. In order for an enterprise to develop, it must be able to transform this data into useful knowledge. Extraction of knowledge from datasets is made possible by Data Mining methods. The paper presents an analysis of the use of Data Mining methods in support of purchases of manufacturing materials. The practical problem of selection of fluxing agents for Submerged Arc Welding (SAW) is solved by applying cluster analysis. The authors present the results of an analysis for 213 combinations of flux-welding wire, conducted by the hierarchical (Ward method) and non-hierarchical (generalized k-means method) cluster methods. The approach proves to be suitable for aiding the decision making process.

Improvement of Acceptance Sampling Inspection for the Operation of Sealing Packages

One of the many purposes for which data are gathered from manufacturing processes is assessment of these processes against predefined criteria. Assessment results are often used for monitoring and supervising the process based on a developed statistical model. This paper looks at the issue of selection of sample size for sampling inspection in the process of packaging medical products. Packaging is an important stage of manufacturing medical products, since the package ensures safety and sterility of the product. In the process of packaging medical products, the operation of sealing the package is of key importance in terms of following medical procedures. Tensile strength of the seal is the critical feature. This paper presents a case study in which an efficient statistical sampling plan was executed for the process of sealing medical packages which led to the saving of time as well as cost.

Possibilities and Limitations of Passive Experiments Conducted in Industrial Conditions

Experimenting is one of the basic tools for design and improvement of products and manufacturing processes. Experiments conducted in industrial conditions should marginally interfere with course of a studied process. These expectations are fulfilled in the best way by so-called passive experiments, in which data is gathered using records obtained from processes conducted in their natural environment and real conditions, without any alteration of set-up parameters. However, it is difficult to control interference originating from variability of studied factors during course of such experiments. That is why use of passive experiments in practice is limited. It is probably caused by distrust regarding credibility of obtained results. Aim of the paper is to compare results obtained from passive and active experiments, conducted in comparable conditions during a process of manufacturing of a selected product and presentation of guidelines for application of passive experiments, developed on the basis of the obtained results.

IMPROVEMENT OF SURFACE LAYER GRINDING PROCESS WITH THE USE OF DESIGN OF EXPERIMENTS METHODOLOGY

The authors introduce the problem of excessive waste of raw material in the wood industry on the basis of the floorboard manufacturing process. The study was aimed to optimize the process of lamella grinding – the final stage in the manufacturing of the oak surface layer. The paper describes implementation of the design of experiments (DoE) methodology to improve the production process of the floorboard surface layer (lamella). The authors made certain assumptions and designed an experiment to obtain high quality lamellas and minimize the waste of raw material. A three -factor full factorial experiment was conducted. The paper presents the conducted study and the authors’ recommendations concerning the determination of optimal machining parameters (on the basis of the results of Experiment 1), parallel arrangement of lamellas (on the basis of Experiment 2), and minimum machining allowance (Experiment 3).