An interactive tool for assessing the performance of precontrol plans

V. Giner-Bosch, A. Carrión, S. San Matías, M. Clemente-Císcar

Precontrol is a quality control tool used for quick assessments of the ability of a process to meet specifications. The performance of a precontrol chart can be measured in terms of its power and of the expected sample size. These measures depend on some process parameters such as the mean shift and the potential capability index and on certain design parameters of the technique which can be set by the user; namely, the number of consecutive safe or close-to-target observations required to qualify the process, the number of consecutive warnings needed to rise an alarm, and the width of the safe zone of the chart. In this work, some mathematical properties of the power and the expected sample size of precontrol are proven. These and other previous results are then used to build a computer app which allows practitioners to simulate different scenarios by showing the performance of precontrol under different settings of the precontrol parameters. A prototype of this software is presented.

Palabras clave: precontrol quality control process capability sample size statistical power scenario simulation

B. Álvarez-Ros, V. Giner-Bosch, T. Carot, V. Soler Baquero

W. E. Ugaz Sánchez, I. Sánchez, A. M. Alonso

M. Campuzano Hernandez, A. Carrión García, C. Rodriguez Moreno

P. Blanco Alonso, M. J. Mures Quintana, M. C. Huerga Castro