Date of Award
Master of Science in Systems Engineering
Mechanical, Industrial and Systems Engineering
A school district was interested in making sustainable changes in their cafeterias to lower their environmental impact. To determine their current state, weight and dimensions of their waste were taken, lunch observations and spaghetti diagrams were developed, and the purchasing process of lunch trays was determined. This was all used to create a current state map, a common industrial engineering tool used in lean manufacturing to display the flow of a system and label problem areas. From there, a life cycle assessment made with Umberto NXT LCA software was created for four lunch trays systems: disposable paper boats, compostable trays if sent to a composting facility, compostable trays if disposed of in a landfill, and reusable plastic trays. This was used to calculate the environmental impact and the results were compared for each tray. After this, a cost analysis was completed. One portion was developed to determine the expense or savings involved in switching to a different tray and/or dishwasher unit than what was already in place at each school level (elementary, middle, and high school). Another involved comparing the estimated amount of trash accumulated over a year with the annual volume of the dumpsters the schools were paying for. Lastly, a future state map was developed to lay out changes that could improve the system of the cafeterias.
The current state showed some areas in need of improvement such as recycling behavior, cafeteria layout of the waste bins, and educational signage. In terms of the weight and volume data collected, the high school had the largest tray contribution to trash when comparing the total weight and volume of the trash with the trays. For the life cycle assessment, reusable trays had the lowest environmental impact based on the impact categories studied. The tray types with the highest impact were the compostable trays if sent to a landfill and the disposable trays. Once the cost analysis was completed, it was determined that while the reusable trays would be the best choice to lower environmental impact, it would be costly for any school level to switch to using them at that time. Switching to new dishwasher units, however, would save the schools money if the initial purchase could be covered. Finally, the future state map created incorporated changes that would resolve the problems noted in the current state map such as the positioning of waste bins and better signage.
Orr, Emily, "SUSTAINABLE WASTE MANAGEMENT IN SCHOOLS" (2020). Open Access Master's Theses. Paper 1854.