Containment to Prevent Automotive Steering Column Electrical Failures
Measure Phase
Date: 21 February 2016
Introduction
The first step we undertook as a team was to measure the number of field failures annually as a result of electrical failures in the steering column electronic(SCE). These failure were as a result of foreign metal debris causing short circuits in the SCE.
At an average cost saving of €5300 per field failure , any reduction of same would have a significant cost saving for our company .
Because of the issues we were having with insufficient conformal coating on our SCE , it was decided to carry out a CMK evaluation on our Nordson coating machine .Analysis of CMK will be performed in the next phase of the DMAIC process, ie the Analyse Phase. CMK was measured using 50 continouous samples produced on our machine , in this case the X, Y and Z axes, keeping all influences other the machine parameters constant. The data was then input into Minitab software to calculate the CMK values for each axes . The industry specification is a CMK value of greater than or equal to 1.67 . CMK values greater than this value indicate that the machine is capable and also that a stable process is achievable .
The most significant part of our Measure Phase was the Design of Experiments(DoE) we carried out to determine the optimum levels for all variables of the conformal coating process, thus giving best possible results, namely sufficient coverage with no delamination (splitting or separation into layers), cracking or bubbles.
The first stage of the DoE process was to screen out the significant variable.See Table2. All machine variables were listed at their low and high settings and the results entered into Minitab software.This generated an array of runs for us to complete (DoE1)and present for analysis. See Table3. The aim of this Design of Experiments is first to identify the significant variables by means of our screening method in DoE1 and secondly to provide an understanding of the significant variable settings and the effect they have on each other. DoE analysis will also be carried out in the next stage of the DMAIC process , ie the Analysis Phase.
At an average cost saving of €5300 per field failure , any reduction of same would have a significant cost saving for our company .
Because of the issues we were having with insufficient conformal coating on our SCE , it was decided to carry out a CMK evaluation on our Nordson coating machine .Analysis of CMK will be performed in the next phase of the DMAIC process, ie the Analyse Phase. CMK was measured using 50 continouous samples produced on our machine , in this case the X, Y and Z axes, keeping all influences other the machine parameters constant. The data was then input into Minitab software to calculate the CMK values for each axes . The industry specification is a CMK value of greater than or equal to 1.67 . CMK values greater than this value indicate that the machine is capable and also that a stable process is achievable .
The most significant part of our Measure Phase was the Design of Experiments(DoE) we carried out to determine the optimum levels for all variables of the conformal coating process, thus giving best possible results, namely sufficient coverage with no delamination (splitting or separation into layers), cracking or bubbles.
Both tools , ie CMK and Design of Experiments were invaluable to us as a team in order to first prove that our machine was capable and also that it was being operated at optimum settings.
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