In engineering approach to new product design, manufacturing and operation it must be ensured that all
variations and uncertainties affecting its performance are considered as far as practicably possible. In order to
achieve it, it is advisable to apply robust design methods. These methods allow for further development of quality
control of products in the manufacturing and operation. Quality control methods based on the parameters estimation
can be applied for simple products in which the linear relation between parameters and outputs can be found. In the
case of more complex nonlinear products the above approach cannot be applied and the application of output
adaptive threshold technique presented in the paper seems to be a promising solution.