Os gráficos de controle como ferramenta de análise do desperdício alimentar em um restaurante universitário

Abstract

Control charts are one of the most important tools of Statistical Process Control (SPC). They were worldwide reported in the 50s, and since then they have became a reference in the search for quality, especially for the popularity gained in the Japanese industry. In this paper, control charts are used to monitor the waste of foodstuffs of the University Restaurant (UR), of Federal University of Santa Maria, in search of undesirable variations and special causes related to distributed meals. For this purpose, data from October 2013, lunch time were used, collected from the three constituent part of the University Restaurant. Data were analyzed based on literature review about the Food and Nutrition Unit as well as on the review of statistical control charts. The average per capita of the food consumed in the UR was 0.60 kg and the despised food could feed 10,038 people. The variable weight of the rest had a normal distribution, which allowed the preparation of traditional control charts for this variable. The control chart for individual measurements, the CUSUM chart and the EWMA chart, developed to analysis of the variable weight of the rest, revealed that food waste generated by the user is within the limits calculated for the average μ = 240.83 kg / day and σ = 79.93 kg / day. However, the graphics designed to control the variable index of rest-intake confirmed the presence of unacceptable levels of waste in four days of study. Unexpectedly, the highest rates of rest-intake refer to Saturdays, when the number of users expressively decreases in the restaurant. Thus, it is important to educate the user about the need to rationalize the food, considering the social, ecological and economic spheres, as well as encourage the use of control charts in the food industry in order to process improvements.