This paper presents a joint use of the T2 chart and total inertial tolerancingfor process control. Here, we will show an application of these approaches in the case ofthe machining of mechanical workpieces using a cutting tool. When a cutting tool inmachining impacts different manufactured dimensions of the workpiece, there is acorrelation between these parameters when the cutting tool has maladjustment due to badsettings. Thanks to total inertial steering, the correlation structure is known. Thispaper shows how T2 charts allow one to take thiscorrelation into account when detecting the maladjustment of the cutting tool. Then thetotal inertial steering approach allows one to calculate the value of tool offsets inorder to correct this maladjustment. We will present this approach using a simpletheoretical example for ease of explanation.

Process performance can be analyzed by using process capability indices (PCIs), which are summary statistics to depict the process location and dispersion successfully. In some cases, quality characteristic and target are not precise numbers and they are expressed in fuzzy terms, so that the classical capability indices cannot be applied. In this paper we obtain a confidence interval for inertial capability index Cpi (defined by [Pillet, TQM Mag. 16, 202–209 (2004)]) based on fuzzy data and propose a membership function for it.

The weighted inertial piloting of processes presented in this paper is a break-away in terms of the quality of machined mechanical workpieces compared to the traditional piloting carried out by machine setters. However, sometimes one has a stability problem during the piloting phase due to over adjustment. We propose to study the causes of this instability and to develop an approach in order to correct the problems. Once we have reminded ourselves of the basics of weighted inertial tolerancing, we will propose an approach to identify the most probable decentring. The applications of the concepts discussed in this article were tested over a period of two months. The results are very convincing, especially with the elimination of the phenomenon previously observed in identical conditions.