Optimization of the Particle Size Distribution of White Sugar Using Six Sigma Methodology

Abstract

The main objective of this paper is to provide a full six sigma approach to control several indicators
characterizing the variability of the white sugar’s particle size at the crystallization station in an emerging African
country such as Morocco. To do this, we first defined our perimeter of study, and subsequently we defined the critical
elements of quality (CTQ) of our project namely: Average Aperture (OM) with a target of 0.6mm and a variation margin
of ± 0.05 and Coefficient of Variation (CV) which varies in the range [38% -45%]. To make a diagnosis of the initial
state of the granulometry we have adopted the study of repeatability and reproducibility as well as the study of the
process capabilities. In order to trace the root causes of the variability in the crystallization process, we carry out an indepth analysis of our process by adopting the experimental plans. The study of desirability identified the combination of
variable parameters that jointly optimize the Average Aperture and Coefficient of Variation. To verify the validity of the
resulting model we realized monitoring and we recalculated the new capability indicators and the level of quality
achieved characterized by Z process. In order to put our process under continuous control we have carried out control
charts. At the end of this project we quantified the gains, a 22.51% reduction in non-quality in white sugar.