Abstract
Production planning is a continuous process that aims to deliver given products at the right time
in the future and targets the best utilisation of the available resources to satisfy the market demand.
This study focuses on how production planning can be integrated with quality control. A myriad
of variants of the problem has been addressed in literature. However, this study focuses on two
major variants observed in a brewing company located in the Gauteng province of South Africa.
The first variant asks for integrating production planning and quality control processes to obtain a
more accurate and realistic production plan, whereas the second variant asks for addressing and
analysing the mutual influence between the three processes, namely production planning, sales
and quality control, and the packaging and warehouse in the brewing company.
The study aims to minimise the disparity between the planned and actual produced volumes, while
considering the integration and the mutual influence between these processes. The study assessed
the variation between planned production volume and targeted production volume for a period of
5 years (2015 to 2019). A quantitative research design was implemented, where the data used were
obtained from the company’s archives. The data showed that there has been a variance between
planned production volume and targeted production volume over the years. The trend assessment
for the period varied throughout the years, but the variation kept on increasing from year to year.
To address this problem, a mixed-integer mathematical model was developed and solved
optimally. The proposed model defines the optimal production and maintenance plan for
production and packaging lines. Furthermore, the developed model considers maintenance
constraints and quality rejection chances. A set of comparisons and results analyses were
conducted and, finally, a set of recommendations are provided.
Key words: Brewing industry, production planning, mathematical modelling, optimisation.