## 4 Case Study--Analysis of Disruptions
### Logistics Process of Container Circulation in the Cold Supply Chain  
The circulation of containers in the process depends on individual customer requirements. There are no formal requirements specifying how such a process should look, so the process may vary for each customer. Also, the transport temperature and the temperature in specific zones in the distribution center (DC) depend on the customer. This makes it impossible to classify temperature readings without defining the temperature requirements for specific zones and/or goods stored in containers (warm, cold, or frozen). The logistics cycle in the analyzed warehouse includes various zones with specific requirements for each process (Figure 3). The cleaning and drying of containers are essential parts of the logistics cycle but can vary depending on the company's internal policies. Cleaning may occur before every cycle, periodically (e.g., once every few cycles), on specific days of the week, or when containers are visibly dirty or emit unpleasant odors. Container drying can be achieved in the following two ways:  
1. Drying in a zone (room) with forced air circulation at a higher temperature than the rest of the distribution center;
2. Drying in a zone without raising the temperature and without forced air circulation. In the analyzed warehouse, the following zones are present:  
* Loading/Unloading Zone: This is where goods received from suppliers are unloaded, and products destined for customers are loaded. It may have a direct connection to the warehouse through entry gates or an indirect connection via intermediate ramps and sluices, depending on the nature of the stored goods and desired conditions inside the warehouse;
* Receiving Zone: This is where goods are received, and processes include order quantity and quality control, cargo sorting, product labeling, determining storage locations,  
Figure 3: A general schematic of the logistics cycle. and possibly subdividing into smaller units. The receiving zone is usually separated from other areas to avoid interference. It may also be connected to the shipping area. * Storage Zone: This is the primary warehouse area where products are stored. The size and layout depend on factors like the type of stored products, turnover rate, available technological solutions (e.g., shelf type and height, machinery, automation systems), storage method (on the floor, on shelves, in racks, etc. ), and other factors. Various equipment and tools, such as forklifts, lifting devices, and cranes, are used in this area;
* Container Cooling Zone: This is where containers are cooled after cleaning and drying. Properly cooled containers are essential for maintaining the required temperature during product transportation;
* Picking Zone: This zone might not exist in every facility but is used for assembling orders. It's typically found in warehouses serving small distributors or retail customers with diverse orders;
* Shipping Zone: In this area, completed orders are packed, labeled, and then sent to the loading area. Efficient operations in the shipping zone require equipment that aids in packing and labeling cargo and ensures a smooth flow of goods between this zone and the picking and loading areas;
* Service Areas: Every warehouse typically includes service areas such as restrooms, offices, changing rooms, customer service desks, and quality control departments. These areas may also include battery charging stations for electric equipment. These zones are vital in managing the logistics cycle effectively. The specific processes and requirements in each zone can vary between warehouses based on the nature of the products and the company's operational policies. Additionally, in warehouses where there is a circulation of logistic containers, the following zones are present:  
* Clearing Zone: This is where containers are cleaned;
* Drying Zone: Containers are dried in this area;
* Cooling Zone: Containers are cooled here. The division of zones may not always be present in every warehouse.