## 3 Case Study: Dairy Industry  
The case study contributes to investigations related to factual and present situations in daily life, with the opportunity to be evaluated and improved. Its main purpose is to analyze and solve problems in various fields. Despite being strongly related to social research, all areas use the case study method, whether associated with issues of the industrial or economic sector, since, regardless of the area of interest, the case study arises with the objective of understanding and investigating real-world situations in a more focused way [24]. The milk production chain has to address the question of the degree of perishable products very carefully, which can vary from days (milk in nature) to months (hard cheeses). A perishable product presents at least one of the following conditions: (1) its physical condition deteriorates visibly; (2) its internal or external value decreases in the customer's perception; (3) the reduction in its functionality can lead to serious consequences [25]. The milk produced, respecting the appropriate conditions imposed by sanitary regulations, is stored in chillers on the properties or in community tanks. Trained professionalsshould perform its collection, performing several product quality tests before transporting it to the processing industries. In Brazil, the person in charge of collection at the property measures the temperature, alkalinity, and acidity of milk [26]. If the milk passes the sanitary requirements, it is transported in isothermal tanks that cool the raw material in conditions suitable for processing. When arriving at the industrial plant, the raw material undergoes inspection, and again, tests are made to ensure that the milk has not undergone changes. In the processing industry, the raw material is stored properly at low temperatures to maintain its quality. The dairy processing plant must coordinate the following three primary processes: (1) the transformation of raw materials into intermediate products, (2) the filling and packaging operations of final products, and (3) the transport of end products to distribution centers [27]. After the inspection approves the milk, it begins its transformation steps until each final product is produced. The dairy processing plants are segmented according to the final product to be produced. It is important to note that before any other process is performed, the milk is pasteurized. Depending on the production purpose, raw materials may suffer nutritional repairs of fat and protein, always from milk. Each industry has peculiarities related to the organization of production and meeting demands. For example, some products can start production in one factory and end up in another, such as cheese that can be produced in one place and sliced in another. For the development of this research, interviews and technical visits were conducted in an important industry, with units in Brazil and around the world, aiming to understand the dynamics related to the production and transportation of dairy products. Figure 1 represents dairy products' production, quarantine, and destination at the distribution center. After production is completed, products enter a quarantine period, except for dependent products. During this time, they remain in storage until released. Once released, dependent products undergo an additional processing stage at the original facility or another plant with available capacity. Final products released from quarantine are then transported to the distribution center. The objective of Figure 1 is to provide basic knowledge of the production dynamics of the entire milk chain since each derivative has a specific way of being produced. The data used are adaptations of accurate information from the dairy production chain. The scope of the research concerns four dairy processing plants and one distribution center. Figure 1: Case study graphic representation.