An approach to the capability analysis of a multi-spindle machining centre

In many industries, there is a growing need to produce products with strict tolerances of individual product characteristics. Increasing productivity and profitability are also sought, demanding the production of more products per unit time, and at a lower cost with the available production equipment and with minimal investment. A Strong competition creates the need to improve production efficiency. One way of addressing the challenge of precise parts manufacturing is by analysing the capabilities of the production equipment. Assessing process capability using statistical modelling plays a key role in the business decision-making process in quality management. This paper presents a statistically based approach to capability analysis of a multi-spindle machining centre

TQM – A WAY TO DIFFERENTIATION

Upravljanje kvalitetom obuhvaća sustavno korištenje različitih metoda, smjernica, tehnika i alata kako bi se, kroz postizanje visoke kvalitete proizvoda i procesa, zadovoljili zahtjevi korisnika i postigla konkurentna prednost te poslovni uspjeh. Buđenje svijesti o kvaliteti u svim poslovnim procesima osnovni je cilj TQM-a, a pretpostavlja orijentaciju na korisnika, kontinuirana poboljšanja i inovacije, timski rad, procesni pristup i dr. Tvrtka u kojoj su uspostavljeni takvi uvjeti poslovanja može prosperirati i stvarati proizvode koji se odlikuju kvalitetom i specifičnošću. Naglašava se da na ostvarivanju takvih uvjeta poslovanja ključnu ulogu ima vodstvo tvrtke. Tvrtke koje uspješno i kontinuirano provode principe TQM-a diferenciraju se na tržištu, stvaraju kvalitetne i prepoznatljive proizvode, imaju zadovoljne i vjerne klijente te motivirane zaposlenike.Quality management includes systematic usage of different methods, guidelines, techniques and tools in order to, through achievement of high quality products and processes, satisfy users’ demands and to achieve competitive advantages and business success. Raising the quality conscience in all business processes is a main goal of TQM, and it assumes users orientation, continuous improvement and innovations, teamwork, process approach et cetera. The company in which these aspects of business are achieved may prosper and create products that are distinguished by specific quality and uniqueness. The emphasis is that the business achievement of these conditions must come from company leadership. Companies that successfully and continuously implement TQM\u27s principles differentiate on the market; create high-grade and recognizable products, satisfied and loyal clients and motivated employees

Factors in Turnaround Refinery (TAR) Project Management Process

Maintenance of process plants such as refinery plants requires implementation of good maintenance practices due to the presence of high complexity. With regard to the aspect of refinery plants maintenance, the most significant undertaking is the turnaround (TAR) carried out through a project task with a long duration of planning and a very short duration of realisation period, which makes it one of the most complex maintenance projects in general. Such maintenance is based on multidisciplinarity that must be implemented through a quality management system at all levels of maintenance management. This paper will define and test factors in turnaround refinery project management process, which also represent the quality factors inherent to the turnaround refinery project. Research findings point to the importance of evaluating leadership, team, policy and strategy in the turnaround refinery project management process

Design for Six Sigma Digital Model for Manufacturing Process Design

The transition to digital manufacturing has become more important as the quantity and quality of the use of computer systems in manufacturing companies has increased. It has become necessary to model, simulate and analyse all machines, tools, and raw materials to optimise the manufacturing process. It is even better to determine the best possible solution at the stage of defining the manufacturing process by using technologies that analyse data from simulations to calculate an optimal design before it is even built. In this paper, Design for Six Sigma (DFSS) principles are applied to analyse different scenarios using digital twin models for simulation to determine the best configuration for the manufacturing system. The simulation results were combined with multi-criteria decision-making (MCDM) methods to define a model with the best possible overall equipment effectiveness (OEE). The OEE parameter reliability was identified as the most influential factor in the final determination of the most effective and economical manufacturing process configuration

Analysis of the Cross-Wire Welding Process Stability

The research paper was prepared within the framework of a project whose aim is to improve the durability of the corrosion protection properties of the product by regulating the input parameters of the cross-wire welding process. Cross-wire welding is a subtype of electric resistance welding. Products made by the cross-wire welding process are widely used in everyday life and can be found in the form of grids, gratings, fencing systems, baskets, guards, etc. The subject of the research work is a preliminary analysis of the stability of the cross-wire welding process. The results of the performed analysis will serve as a starting point for the second phase of the project. Since the recorded values of the set down output parameter differ significantly from the expected values, this parameter is considered as an indicator of the process stability. From the specific trend of the results in the performed analysis, it was concluded that the position of the electrode has a significant influence on the result, which was confirmed by comparing the test results before and after the preliminary tests

Development of a Model to Support the Management of the Resistance Welding Process

The work was carried out as part of a project to improve the corrosion resistance of welded joints. The optimal selection of input parameters reduces the consumption of welded material as well as the negative impact on the environment. The samples were welded by electrical resistance welding, more precisely by cross-wire welding. Electric resistance welding is a process for welding with electricity in which of high electrical resistance is used to generate heat at the contact point of the welded parts. Steel wire S235 with a diameter of 4 and 3 mm was used. The article shows the creation of the model to predict the percentage of setdown and weld strength as a function of the input parameters, welding current and welding time. The first task was to create a Design of experiments in which the process parameters or the range of input parameters are determined. The Design of the experiments was created for both wire diameters. This covers the range of parameters with which a welded joint of wires can be realised. A statistical analysis of the process follows, where it was found that for 4 and 3 mm diameter wires the percentage setdown increases with increasing welding current and time. An increase in strength as a function of welding current and welding time is also observed, but the results overlap in most cases and the range of their values is greater than that of setdown. The appearance of the weld was analysed for each sample. The visual inspection revealed seven categories of welds, which were divided into two groups, i.e. good and poor welds. All results were listed in a table with the percentage of expectation for a particular category of weld appearance. Based on the analysis, a model for determining the welding result parameters depending on the specified input parameters was developed, which can be used in practise to support the management of the electric resistance welding process

Alati osiguranja kakvoće kod lijevanja košuljica cilindara brodskih sporokretnih motora

Radom je istražena mogućnost praktične implementacije procesa neprekidnog unapređivanja kakvoće kod lijevanja košuljica cilindara brodskih sporokretnih motora, temeljenog na alatima osiguranja kakvoće, u tvornici 3. maj Motori i dizalice d.d. Cilj provedenog istraživanja bio je pokazati uspješnost primjene dostupnih alata osiguranja kakvoće radi smanjivanja troškova, povećanja produktivnosti, organiziranoga praćenja procesa, utvrđivanja sposobnosti i djelotvornosti sustava upravljanja kakvoćom, otkrivanja kritičnih značajki i podizanja razine kakvoće. Dobiveni rezultati nalaze primjenu ponajviše u promatranom procesu s mogućnošću primjene i na druge procese u proizvodnji brodskih sporokretnih motora općenito