Cummins ISB LTMS2. This package contains charts and figures that supplement the LTMS2 template put forth by Statistics Task Group. LTMS2 Template document name: “Cummins ISB LTMS Version 2 Proposal.docx”
This package contains charts and figures that supplement the LTMS2 template put forth by Statistics Task Group.
LTMS2 Template document name:
“Cummins ISB LTMS Version 2 Proposal.docx”
The LTMS2 template contains possible values for the various chart limits. Page 2 of this document summarizes these values.
Pages 3-11 show the control charts and alarms of LTMS1 and proposed LTMS2.
Pages 12-14 contain some comments on Excessive Influence calculations and alarms in LTMS1&2.
November 30, 2010
focus: Shewhart severity (Y) alarms
focus: e alarms
Comparisons LTMS1 / LTMS2
focus: number of reference interval extensions and reductions
Reference Interval Extensions and Reductions
37 total reference oil results
12 were calibration tests
37-12=25 tests were eligible for extended intervals
9/25 (36%) received extended intervals in LTMS2
7/37 (18.9%) failed in LTMS2
overall for all labs
Tappet weight loss severity charts showing Excessive Influence calculation
Excessive Influence calculation adjusted Y results from green filled circle to cyan circle.
Tappet weight loss precision charts showing e
These are examples of results that trigger alarms in LTMS2 but not LTMS1. While their Y results are not excessive, their e values are high (~1.1) because they outlie the lab’s Z baseline (~-0.9).
This is an example of a result that would trigger alarm in either LTMS1 and LTMS2. It has a high Y value that exceeds LTMS1 limit. It has a high e value because its result (~2.8) outlies the lab’s Z baseline (~0.1).
The dotted line is Level 2 e alarm, and solid line Level 3 e alarm