As part of continuous quality improvement in well-managed enterprises, identifying unconformity should initiate actions to find their causes. Therefore, it was proposed to the enterprise located in Podkarpacie to use in the sequential way the Ishikawa diagram and 5Why method. The aim was to analyse of unconformity (porosity cluster) on the turbine outlet nozzle and identify the root of its creation. In the enterprise, the quality analysis of the products with a fluorescent method was carried out, but after identifying the unconformity, non-analysis of their reason for their occurrence was not practiced. Therefore, it was intentional to propose the use of sequence i.e. Ishikawa diagram and 5Why method to identify the root of unconformity. The subject of study was the turbine outlet nozzle, on which the fluorescent method the porosity cluster was identified. With the use of the Ishikawa diagram, the main cause of the problem was pointed (unconformity during production), and by the 5Why method the root cause of the problem, i.e. unconformity material from the supplier, was identified. The proposed method sequence is a simple and effective way to make analyses of unconformities and it can be used in different products and service enterprises.
The analyses of the nonconformity of products are made in order to achieve the desired level of their quality. This is also the case in the analyzed enterprise located in south-eastern Poland. Due to production character in this enterprise to identify the incompatibilities of products the non-destructive tests are used. In the current approach to quality after identified the nonconformities the cause her arise were determined, it was noted in order to use by statistical analyzes. Unfortunately, no deeper qualitative analyzes were made which could specify the source of its creation. Therefore, it was considered that it is necessary to propose to use (near current actions according to non-destructive tests) the sequence of quality management instruments. In order to improve the quality control actions, the sequence of techniques which complement each other, i.e. non-destructive tests, Ishikawa diagram and 5Why method, was proposed. To demonstrate the effectiveness of the proposed sequence, the rear cover of the bearing turbine was selected as the subject of the analysis. The choice was conditioned by the unit character of production, which till now was discouraged a detailed analysis of sources of nonconformities. After analyzed the product with used the fluorescent method the nonconformities were identified on the rear cover of the bearing turbine, which was the porosity cluster. In order to identify the causes these nonconformities the Ishikawa diagram was drawn up. Next, the selected main causes (i.e. supplier of the product and nonconformities created during the production of the product) were analyzed the 5Why method in order to identify the source cause of the problem. In this case, it was the nonconformity material from the supplier. The proposed sequence, which uses the minimal resources let to show the wide range of information, which should be used to the improvement of quality. The presented the set of activities can be practised in each of the enterprises to analyze quality problems in order to identify the nonconformities and their causes.
The research of railway track surfaces is aimed at improving the quality of railway infrastructure and providing the chance of improving the safety of driving. Therefore, it is advisable to constantly monitor track surface, but the research itself is not innovative because it is based on a known procedure. The crucial element are the techniques that allow to delve into the sources of problems. The aim of the article is to use the selected instruments of quality management to analyze the causes of track twist at high (180 km/h) speed of driving. The analysis of the causes of track twist was done on the basis of results from the measurement of one kilometer track section of the Krakow Glowny - Medyka route, which was made by using the TEC measuring device in April 2018. It was inferred that it is impossible to reach 180 km/h without track twist. In order to identify the causes of track twist it was proposed to use the selected sequence of quality management instruments, i.e.: brainstorming, Ishikawa diagram and the 5Why method. The identified causes of track twist include the abrasion of rail, scratches and exploitation point. The analysis and conclusions drawn from it may be useful in the analysis of other problems in railway transport as well as production and service industries.