The data means were analyzed before and after Press operation
and results showed that there wasn’t significant difference between
group means, but although the factor of significance wasn’t smaller
than 5 % it was very close (5,3 %) so obtained result should be
taken with care. It was obviously that something affect normality of
data during the Press operation and, after detailed analyses of all
process conditions, it was decided to do additional analysis taking
into consideration three-positioning points (N) in the casting parts,
Figure 5. Also, additional measurements are made to check
influence of burrs size to the variability of part dimensions.
Results of Analysis of Variance, Figure 6, provide basis for
conclusion that the size of burrs have direct influence on output
dimension. Further data drilling, using box-plot, Figure 7, showed
that higher size of burrs impact higher variation in the process.
The applied Correlation analyses also showed that increase in
burrs result with decrease in dimension on base N. Results on Figure
8 showed that in the base N1 and N2 correlation is different from
zero, while in the base N3 correlation is equal to zero which means
that there aren’t linearity correlation between observed variables