Food supply chains are complex, with many actors in supply, production, distribution, retail, and consumption all contributing to waste. One example is the confectionery supply chain, which is the focus of this research. Many companies, both confectionery and food in general, are looking to reduce their waste, but determining what changes to make can be challenging. An estimated 385,000 tons of food were wasted in Norway in 2017, and while total efficiency is not possible, there is still great potential to improve yield and decrease waste. From the manufacturing perspective, one way to accomplish this is by improving planning and control processes to prevent waste from being generated in the first place so that other waste management techniques are unnecessary. However, before improvements can be made, the root causes of the waste must be assessed and understood.
The purpose of this project is to find insights and relationships between production planning and control (PPC) and food waste that can be used for improvement or further testing recommendations in confectionery manufacturing. This was done through a literature study and a quantitative and qualitative case study involving a confectionery manufacturer. The following research objectives were formulated in line with this overall purpose:
RO1: Investigate relationships between production planning and control and food waste generation. RO2: Make recommendations for how production planning and control can be used to reduce food waste and how this problem can be studied further.
To address these objectives, root cause diagrams were developed using common waste causes found in literature, the concept of an inventory material balance, and the current reality tree method. These causes were grouped into Demand Management factors and Production and Inventory Management factors. The root cause diagrams were then used as input to the analyses to determine the possible hypotheses and propositions to test. Hypotheses were tested quantitatively while propositions were analyzed qualitatively. The hypotheses were analyzed using correlation and regression techniques to determine their possible relationships to two kinds of food waste in the case study: scrap (physical waste) and sell-out (profit waste). The relationships were found to be different between scrap and sell-out waste. Likely relationships to scrap food waste were found for batch size minimum and coverage requirements. In addition, a likely relationship was seen between real production batch size coverage and sell-out food waste. There were other relationships seen, but the results were inconclusive due to the potential underlying impact of perishability on the independent variables tested. For scrap waste, the null hypothesis could not be rejected for batch size averages, and for sell-out waste, the null hypothesis could not be rejected for batch size minimum and coverage requirements.
The propositions were qualitatively analyzed using the case study description created from interviews, observations, and process document review. Each proposition was then ranked into three categories (high, medium, and low) according to the priority they should be given in future studies on this topic, and these results were used as input to RO2.
For RO2, recommendations for further research and improvements were discussed separately for the hypotheses and propositions. For further study, it is recommended that high-priority causes be studied first, followed by the medium- and low-priority causes. Relationships were also seen between product attributes (trade guarantee, category, and country of origin) and food waste, and these attributes should be included in future studies as well to improve the overall data model.
For improvements, two overall recommendations were proposed: 1. Make sustainability a higher priority in strategy and operational PPC2. Increase vertical integration
Overall, this project helped provide a better understanding of how production planning and control is related to food waste in confectionery supply chains.