SAP’s Lean Warehouse Management (Lean WM) is a streamlined version of the full Warehouse Management System (WMS). It allows organizations to manage goods movements efficiently without the complexity of tracking inventory at the storage bin level. Instead, inventory is managed at the storage location level, making it ideal for warehouses that don’t require detailed bin-level stock updates.
How Does Lean WM Work?
Unlike the standard WMS, which tracks stock changes down to the bin level using Quants, Lean WM focuses solely on processing goods receipts and goods issues. The key processes remain similar, as Lean WM uses deliveries and creates transfer orders (TOs) to facilitate warehouse movements. These transfer orders also serve as pick lists for warehouse operations.
Key Features of Lean WM
- Simplified Inventory Management:
- Stock is updated only at the storage location level, not at the storage bin level.
- Ideal for warehouses where bin-level stock tracking is unnecessary.
- Transfer Orders as Pick Lists:
- TOs function as picking instructions and provide flexibility for order handling.
- You can reprint or split transfer orders to distribute tasks effectively.
- Integration with HR:
- TO data, including target metrics and processing staff names, can be passed to SAP HR for incentive calculations.
- Consistency Across Warehouses:
- Lean WM enables uniform processes across multiple warehouses, even if some use full WMS while others implement Lean WM.
Advantages of Lean WM
- Reprinting Transfer Orders:
- Allows easy access to picking instructions for operational flexibility.
- Task Distribution:
- Splitting TOs optimizes workload distribution among warehouse staff.
- Simplified Configuration:
- Reduces the complexity of system setup compared to full WMS.
- Cost-Effective Implementation:
- Suitable for fixed bin warehouses where detailed tracking is unnecessary.
Limitations of Lean WM
- No Bin-Level Stock Updates:
- Stock quantities are only visible in Inventory Management (IM) and not in WM stock overviews.
- Bin-level stock differences cannot be processed in WM; adjustments must be handled in Inventory Management (MM-IM).
- Fixed Bin Warehouses Only:
- Random storage is not supported in Lean WM.
Configuration Prerequisites for Lean WM
To implement Lean WM, you must meet the following configuration requirements:
| Configuration Step | Details |
|---|---|
| Storage Location Assignment | Assign a newly created storage location to a warehouse number. |
| Storage Types Setup | Create at least two storage types: |
| – Picking Storage Type: Serves as the source for picking activities. | |
| – Shipping Area: Acts as the destination for outbound deliveries. |
- Storage Location Assignment:
- Assign a newly defined storage location to a warehouse number.
- Storage Types:
- Create at least two storage types:
- Picking Storage Type: Used as the source for picking activities.
- Shipping Area: Serves as the destination for outbound deliveries.
- Create at least two storage types:
When to Use Lean WM
Lean WM is ideal if you need the advantages of WMS, such as transfer order functionality, without the overhead of managing bin-level stock data. It is particularly beneficial for:
- Fixed bin warehouses with minimal storage complexity.
- Warehouses already using standard WMS but requiring a simplified system for additional locations.
Conclusion
Lean WM offers a flexible, simplified solution for managing goods movements while maintaining essential warehouse functionality. By focusing on goods receipts, goods issues, and transfer orders, Lean WM enables businesses to optimize operations without the need for complex bin-level stock management. It is a cost-effective choice for warehouses with fixed bins, ensuring streamlined processes and consistent operational standards.