Integrating SAP PP (Production Planning) and WM (Warehouse Management) for creating picking lists of components against production orders can present several challenges.

Here are some common issues:

1. Data Synchronization: Ensuring that data between PP and WM is synchronized accurately can be challenging. Any discrepancies can lead to incorrect picking lists and production delays.
2. Batch Determination: Automating batch determination for components can be complex, especially when dealing with multiple batches and varying stock levels.
3. Storage Location Management: Managing storage locations and ensuring that components are picked from the correct locations can be difficult, particularly in large warehouses with multiple storage areas.
4. Transfer Orders (TO) and Transfer Requirements (TR): Creating and managing TOs and TRs can be cumbersome. Ensuring that the correct quantities are transferred and reflected in the production order is crucial.
5. Real-Time Updates: Keeping the picking lists updated in real-time with changes in stock levels, production schedules, and other factors can be challenging.
6. Customization and Configuration: Configuring the system to meet specific business requirements and workflows can be time-consuming and requires a deep understanding of both PP and WM modules.
7. User Training: Ensuring that warehouse staff and production planners are adequately trained to use the integrated system can be a challenge. Proper training is essential for smooth operations.
8. Error Handling: Identifying and resolving errors in the picking process, such as incorrect picks or missing components, requires robust error-handling mechanisms.

Addressing these challenges requires careful planning, accurate configuration, and continuous monitoring of the integrated system. Regular audits and feedback loops can help in identifying and rectifying issues promptly.