EVALUATION OF PRODUCT QUALITY WITH DECIBELS

In modern Quality Engineering, the quality of process results, the quality of measuring instruments, and the quality of completed processes are considered according to their quality characteristics. However, in traditional engineering, only the quality of measuring instruments and the quality of completed processes (precision or accuracy indices PCI, PPI) can be successfully defined, while the quality of process results (semi-finished product, product, software, service) can only be described (has or does not have the required quality), good or bad quality, better or worse quality). In the modern consideration of quality, the quality of process results is now defined by the number of decibels [dB], according to the discovery of the genius Japanese scientist Genichi Taguchi (1924-2012), with the methods of Robust Technology Development and Standard Ratio (S/N). This paper discusses definition of the quality of process results with one input variable and continuous characteristics with three illustrative examples.