3. The problem at the current manufacturing plant
The data in this section were collected during a performance improvement project carried out by the B2B
Manufacturing Centre1 to assist a manufacturing plant to improve quality performance. The project is intended as an
application of a new key performance indicator called ‘batch effectiveness factor’. The performed tasks were:
investigation of the operational effectiveness of the manufacturing processes, analysis of quality performance,
proposal of practices for quality improvement. The analyses were carried out to define the defect rate in
the final products. The observations shown in Fig. 4 indicate that the daily defect rates are significant. Most of
these rates range between 10% and 15%, although some
rates were found to be out of this range, i.e., day five was
34.6%, day six was 19.2%, and day seven was 6%, as
shown in Fig. 4. Defect rate was calculated by the following
method:
%Defect rate ¼ ðbad production=total productionÞ 100
or
%Defect rate ¼ 100 quality rate%.
In Table 1, the occurrences related to each cause are
shown. The number of defects caused by inclusion is the
highest amongst all other causes at 71.43% of total defects.
Defects caused by scratches and fibers are 12.91% and
11.48%, respectively. These figures increase the possibility