'Politechnika Slaska - Silesian University of Technology'
Doi
Abstract
The basic objective of this paper is to present the possibilities of applying selected quality tools in analysing the reasons for discrepancies as exemplified by the process of manufacturing wet refractory mortars. Using various methods and tools, the authors looked for the root causes of a quality rejects occurrence. The following selected methods and tools were used: analysis of variance - ANOVA, the individual moving range (I-MR) chart, SIPOC process mapping, analysis of regression, identification of potential root causes of a problem - 7M, Gauge Repeatability and Reproducibility (GRR). The paper shows how it is possible to search for the causes of quality rejects by means of deliberately selected tools and methods and to successfully decrease the number of discrepancies after introduction of the appropriate corrective actions. The authors indicate how it is possible to analyse the processes of manufacturing wet refractory mortars and what can be done in the situation when a faulty measuring system (returning seriously erroneous results) is the reason for a lack of or lower detectability of wet mortar flaws as it has affected the accuracy of feeding of all components of the recipe, as well as the consistency, moisture content, and hardness/softness of mortar. The collected analysis results allowed the authors to conclude that there were seven probable root causes influencing the hardening of mortar and the loss of its primary functions. This paper could be useful for those wet refractory mortars manufacturers who find it difficult to build their knowledge about product properties based on available publications sources
