Abstract:
This study is mainly concerned about the production of hot water bottles by a
bottle manufacturer in Galle. The main problem encountered by the
manufacturer was the increase of number of defects in the product. This
problem could have been arisen due to variation in the quality of rubber
material used. Viscosity, hardness, TS2 and TC90 are four main factors of
the rubber compound that needed to be considered. At present, some specific
ranges of above factors are used as quality standard limits, but it appears that
the values are incorrect. Therefore, this study was conducted to identify
appropriate control limits of above factors to get high quality products. The
main objective of the research was to reduce number of defects by
controlling the limits of four main factors. Descriptive statistical analysis has
been used to obtain the appropriate limits for the above factors, and multiple
regression analysis technique is used to obtain the regression model which
describes the relationship between the defect proportion percentage and the
above factors. Simulation techniques were used to compare the number of
defects that may be obtained using current range and the proposed range.
The improved ranges were used to check whether defects of the production
process has reduced.
