Patent ID: 7673247

Claim:
A computer-implemented method of relating control limit values to noncomplying points, the method comprising: receiving from a user a selection indicating two or more datapoints to be used in a control limit operation; identifying two or more processes from which the datapoints were derived; calculating a first control limit value for a first process based on one or more datapoints associated with the first process, the first control limit value indicating one or more noncomplying points that are not within an expected range for the first process; calculating a second control limit value for a second process based on one or more datapoints associated with the second process, the second control limit value indicating one or more noncomplying points that are not within an expected range for the second process; generating a graph by: creating, on the graph, a single two dimensional coordinate axis, and displaying the first and second control limit values relative to the noncomplying points for at least the first and second processes, such that both of the first and second control limit values are displayed continuously as a series of interconnected parallel steps reflecting the first and second control limit values on the graph and in relation to the single two dimensional coordinate axis; and identifying the noncomplying points in the generated graph.