## 4 Case Study
### The Method Employed in this Study Is Illustrated in Figure 7
#### 4.1.2 Phases 2 and 3: Do and Check
\begin{table}
\begin{tabular}{l c c c c c} \hline \hline
**Process Data:** & \multicolumn{5}{c}{**Overall Capability**} \\ \hline \multicolumn{2}{c}{**Short-Side Armature**} & \multicolumn{2}{c}{**Long-Side Armature**} & \multicolumn{2}{c}{**Short-Side Armature**} & \multicolumn{2}{c}{**Long-Side Armature**} \\ \hline LSL & 58.8399 & 58.8399 & PPL & 0 & 0.47 \\ \hline Sample mean & 58.5133 & 141.347 & Ppk & 0 & 0.47 \\ \hline Sample N & 30 & 30 & Potential (within) capability \\ \hline Overall StDev & 28.0494 & 58.3937 & CPL & \(-\)0.01 & 0.45 \\ \hline StDev (within) & 17.6576 & 61.4867 & Cpk & \(-\)0.01 & 0.45 \\ \hline \multicolumn{2}{c}{Performance:} \\ \hline \multicolumn{2}{c}{} & \multicolumn{2}{c}{Observed} & \multicolumn{2}{c}{Expected Overall} & \multicolumn{2}{c}{Expected Within} \\ \hline \multirow{3}{*}{PPM \(<\) LSL} & Short-Side Armature & Long-Side Armature & Short-Side Armature & Long-Side Armature & Armature \\ \hline PPM \(<\) LSL & 500,000 & 33,333.33 & 504,644.93 & 78,835.22 & 507,378.31 & 89,818.74 \\ \hline PPM total & 500,000 & 33,333.33 & 504,644.93 & 78,835.22 & 507,378.31 & 89,818.74 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Detachment force capability response to curing station voltage increase. Figure 19: Histograms of detachment force capability response to curing station voltage increase: (**a**) short-side armature; (**b**) long-side armature. sides; the short side increased from 0 to 0.05 (Table 9 and Figure 20), and the long side, from 0.47 to 0.69 (Table 9 and Figure 20). While encouraging, these values still fall short of the company's minimum acceptable Ppk of 1.32, indicating further optimizations are needed. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**(a)**} & \multicolumn{6}{c}{**(b)**} \\ \hline  & **N** & **Mean** & **StDev** & \
\begin{tabular}{c} **SE** \\ **Mean** \\ \end{tabular} & **N** & **Mean** & **StDev** &
\begin{tabular}{c} **SE** \\ **Mean** \\ \end{tabular} \\ \hline C3 & 30 & 58.5 & 28.0 & 5.1 & C4 & 30 & 141.3 & 58.4 & 11 \\ \hline C5 & 30 & 61.3 & 15.5 & 2.8 & C6 & 30 & 114.4 & 27.0 & 4.9 \\ \hline \multicolumn{6}{c}{C3 = Data before 2 nd experiment} & \multicolumn{6}{c}{C4 = Data before 2 nd experiment} \\ \hline C5 = Data after 2 nd experiment & \multicolumn{6}{c}{C6 = Data after 2 nd experiment} \\ \hline Difference = \(\mu\) (C3)—\(\mu\) (C5) & \multicolumn{6}{c}{Difference = \(\mu\) (C4)—\(\mu\) (C6)} \\ \hline Estimate for difference: \(-2.75\) & \multicolumn{6}{c}{Estimate for difference: 26.9} \\ \hline
95\% CI for difference: (\(-14.53\), \(9.04\)) & 95\% CI for difference: (3.2, 50.7) & \\ \hline T-Test of difference = 0 (vs \(\
eq\)) & \multicolumn{6}{c}{T-Test of difference = 0 (vs \(\
eq\))} \\ \hline T-Value = \(-0.47\) & \multicolumn{6}{c}{T-Value = 2.29} \\ \hline \(p\)-Value = 0.641 DF = 45 & \multicolumn{6}{c}{\(p\)-Value = 0.027 DF = 40} \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Mean difference test results for breaking force before and after increasing the epoxy coating thickness: (a) short-side armature; (b) long-side armature.