QM: New Types of Quality Control Charts

Description

Control chart types

In Release 4.0A, the Customizing application contains the following new control chart types for qualitative characteristics and quantitative characteristics with small sample sizes (see Quality Management -> Quality Planning -> Basic Data -> Sample, SPC -> Control Chart -> Define control chart type):

The c-chart and u-chart are provided for characteristics whose control indicators specify the confirmation of defects. The moving-range chart is a control chart with two tracks that is especially suited for characteristics with a sample size of n=1. In this case, track 1 displays the actual measured value and track 2 displays the distance between the actual measured value and the preceding measured value.

The control limits for the moving-average chart, EWMA moving-average chart, and the R-track of the moving range chart do not only reference the current sample and you cannot use them to valuate the samples.

New programs

The algorithms for the new control chart types are contained in the following function modules:

QRKT_C_SHEWHART
QRKT_EWMA_2
QRKT_MEAN_VALUE_SHEWHART_R2
QRKT_MOVING_AVERAGE_2
QRKT_MOVING_RANGE_SHEWHART_K
QRKT_NP_SHEWHART
QRKT_P_SHEWHART
QRKT_U_SHEWHART