A high amount of costs in a warehouse are caused by picking processes. Some factors like stock turnover, seasonality of products or stock level can hardly be influenced by the persons responsible in the warehouse, but it is their duty to define processes as lean as possible. The most effective ways to optimize the efforts needed seem to be better warehousing, batching of orders, and route optimization. Especially when stock turnover is relatively stable, and product attributes are similar, the picking process itself can be automated. Therefore capital assets rise, and costs for manual work decrease. But if there is a strong variation in workload, or heterogeneous items are to be picked, a manual picking process suits best. This master thesis deals with process types of picking replenishment in trading warehouses, and gives an overview of known alternatives in replenishment techniques and picking systems. The associated core processes to warehousing are introduced, and a brief preview of new developments is given. Next is a case study about methods and processes of picking and replenishing in an Austrian furniture trading company´s warehouse. To reach the goal of reducing the effort needed, various methods of zoning the reserve and the picking area are worked out and compared. One of the most important constraints is that no rise in capital asset is allowed, so the workload of every scenario developed has to be handled with the existing amount of staff and equipment. The result is a comparison of key performance indicators of the existing processes and the possible future scenarios, and a recommendation how to reorganize the processes in order to optimize the picking process and its related supplying actions. Several different set of processes are developed, to visualize the impact of process reengineering on different roles in the warehouse. A significant decrease of workload can be achieved by reorganizing supplying and picking processes, depending on the used storage techniques the results vary slightly.