The company Notino has complex warehouses with several floors. Tens of thousands of orders containing several products are handled daily in these warehouses. A conveyor belt with boxes passes through each floor of the warehouse. The goods for each order are collected in picking boxes on the conveyor belt. On each floor, a picking box is either sent on or filled with products for designated orders. The pickers (people) on each floor are assigned several picking boxes and fill them with the required products. Order delays must be minimized, and the workforce, i.e., the use of pickers, needs to be optimized.

The thesis will start with the study of literature on warehouse planning with a concentration on order picking where multiple floors are needed. The thesis aims to propose and implement the planning of orders on multiple floors by selecting the proper floors for each order and batching them into pick boxes on each floor. The proposed processes will be evaluated with the help of a simulator using simplified procedures for remaining lower-level processes. The evaluation of the thesis will be completed with the help of real-life data provided by the company Notino.