Introduction
Cutover planning is a high-stakes phase in any SAP project, and when it comes to SAP Extended Warehouse Management (EWM), the process of disconnecting and reconnecting from your ERP system (typically SAP ECC or S/4HANA) demands meticulous planning and execution. A misstep here can lead to data inconsistencies, operational downtime, and significant business disruption.
This blog post provides a detailed guide on safely disconnecting your SAP EWM system from ERP during cutover, along with critical steps for a smooth restoration.
Why Disconnect SAP EWM During Cutover?
The primary reason for disconnecting EWM from ERP during a cutover is to prevent the flow of transactional data between the two systems while fundamental changes are being applied in the ERP. This includes:
- Master Data Load: Loading new or mass-changed master data (materials, vendors, customers, batch data, etc.) into ERP.
- Organizational Structure Changes: Implementing new company codes, plants, storage locations, or profit centers in ERP.
- Transactional Data Migration: Migrating open sales orders, purchase orders, production orders, and stock figures into the new ERP landscape.
- System Upgrades/Conversions: If the cutover involves an ERP upgrade (e.g., ECC to S/4HANA) or a major system conversion.
Without a disconnection, the constant inbound and outbound messages between EWM and ERP could lead to data corruption, failed IDocs, and complex reconciliation efforts.
Phase 1: Disconnecting SAP EWM – The Pre-Cutover Checklist
Before you even think about hitting the “disconnect” button, a thorough preparation phase is paramount.
1. Communication and Stakeholder Alignment
- Communicate Downtime: Clearly communicate the planned EWM and ERP downtime to all relevant business users, warehouse operations, and IT support.
- Define Cutover Window: Establish a precise cutover window during which EWM will be disconnected. This should be agreed upon by all stakeholders.
- Escalation Matrix: Define clear escalation paths for any issues encountered during the disconnection or reconnection process.
2. Complete All Open EWM Transactions
This is perhaps the most critical preparatory step. All physical and logical warehouse activities must be brought to a halt.
- No Open Warehouse Tasks (WTs): Ensure all warehouse tasks are confirmed. This includes picking, packing, putaway, internal movements, and physical inventory tasks.
- No Open Warehouse Orders (WOs): All warehouse orders should be fully processed.
- No Open Deliveries in EWM:
- Inbound Deliveries: All goods receipts must be posted and putaway completed.
- Outbound Deliveries: All goods issues must be posted, and loading completed.
- No Open Posting Changes: All stock category changes or stock type changes should be completed.
- Clear Queues:
- qRFC Queues (SMQ1/SMQ2): Ensure both outbound (EWM to ERP) and inbound (ERP to EWM) qRFC queues are empty. Pay special attention to queues related to goods movements, deliveries, and master data distribution.
- BD87 (IDoc Monitoring): Confirm no unprocessed inbound or outbound IDocs related to EWM-ERP communication.
3. Stop New Document Creation
- Block Inbound/Outbound Delivery Creation: Implement measures in ERP to prevent the creation of new inbound or outbound deliveries that would normally flow to EWM. This can be done via:
- Shipping Point Blocking: Temporarily block relevant shipping points in ERP.
- Route Blocking: If routes are used for delivery determination.
- User Exits/BAdIs: Custom logic to prevent delivery creation based on specific criteria.
- Stop Production/Process Order Releases: If your EWM is integrated with production, ensure no new production or process orders are released that would trigger material staging to EWM.
4. System Configuration Snapshot
- Take Backups: Perform full system backups of both EWM and ERP. This is your ultimate safety net.
- Configuration Documentation: Document critical integration settings in both EWM and ERP, such as:
- RFC Destinations (SM59)
- Logical Systems (SALE)
- Distribution Models (BD64)
- Queue Names for qRFC (SMQR/SMQS)
- EWM-specific customizing for delivery integration (e.g., document types, item categories, process profiles).
Phase 2: The Disconnection Process (Step-by-Step)
Once the pre-cutover checklist is complete and you are within the agreed-upon cutover window, proceed with the following steps:
1. Stop All EWM-Related Background Jobs
Identify and stop any scheduled background jobs in both EWM and ERP that are responsible for data transfer or synchronization between the systems. This could include jobs for:
- Master data distribution (e.g., material master, batch master).
- Delivery processing (e.g., outbound delivery creation, goods issue posting).
- Physical inventory.
2. Disable RFC Communication (SM59)
- In ERP: Go to transaction and for the RFC destination pointing to EWM, either:
SM59- Temporarily Disable: Change the user or password to an incorrect one, effectively disabling the connection.
- Delete (with caution and documentation): For highly controlled cutovers, you might temporarily delete the RFC destination, but this requires more careful recreation.
- In EWM: Similarly, disable the RFC destination pointing back to ERP.
3. Deactivate Distribution Models (BD64)
- In ERP: Use transaction to temporarily deactivate or delete the distribution model entries that are responsible for distributing master data (e.g., MATMAS, CREMAS) and transactional data (e.g., DELVRY, SHPORD) from ERP to EWM.
BD64 - In EWM: While less common, review if there are any outbound distribution models from EWM to ERP that need to be deactivated.
4. Stop Queue Processing (SMQS/SMQR)
- In ERP: Use (QOUT Scheduler) to deregister or stop the outbound queues that send data to EWM.
SMQS - In EWM: Use (QIN Scheduler) to deregister or stop the inbound queues that receive data from ERP. This ensures no lingering messages are processed.
SMQR
5. Lock EWM Users
- Lock All EWM Users: To prevent any accidental activity in EWM during the cutover, lock all business users. Keep only the technical users required for monitoring or system administration.
6. Verify Disconnection
- Test RFC Connection: Attempt to test the RFC connections that were disabled. They should now fail.
- Check Queues (SMQ1/SMQ2): Monitor (outbound) and (inbound) in both systems to ensure no new entries are being generated for EWM-ERP communication. Any pending entries should be resolved or cleared if safe to do so (e.g., if they are old and irrelevant).
SMQ1SMQ2 - Try Creating a Delivery: Attempt to create a delivery in ERP that would normally go to EWM. It should now fail to create the EWM delivery.
Phase 3: ERP Cutover Activities
With EWM safely disconnected, you can now proceed with your core ERP cutover activities, such as:
- Loading new master data.
- Migrating open documents and stock.
- Performing configuration changes.
- Executing system upgrades or conversions.
Crucially, ensure that all stock figures and open documents in EWM are aligned with the new ERP data after migration. This often involves:
- Initial Stock Upload to EWM: Once ERP stock figures are finalized, use relevant interfaces (e.g., , /SCWM/ADGI) to upload the initial inventory balance into EWM, overwriting the old data. This is typically done after a full physical inventory count.
/SCWM/IS_STOCK_MIG - Delivery Migration to EWM: If open deliveries are migrated in ERP, ensure they are also replicated to EWM through the appropriate interfaces (e.g., using or similar IDoc types).
DLV_CREATE_FROM_DATA
Phase 4: Restoring SAP EWM – The Reconnection Checklist
Reconnecting EWM requires the same level of precision as disconnection, but in reverse.
1. Verify ERP Data Consistency
- Crucial Step: Before reconnecting, thoroughly verify that all ERP master data and transactional data relevant to EWM is consistent and accurate. This includes material masters, batch data, stock figures, open deliveries, etc. Any inconsistencies here will immediately flow to EWM upon reconnection and cause issues.
2. Clear EWM Master Data (if necessary)
- If your cutover involved significant master data changes in ERP, you might need to clear and reload relevant master data in EWM. Tools like can be used for products.
/SCWM/R_MIG_PRODUCT_LOAD
3. Align EWM Stock with ERP
- Absolute Must: Ensure that the physical stock in EWM precisely matches the logical stock in ERP. This is often achieved through:
- Physical Inventory: A full physical inventory count in the warehouse, with results posted to both EWM and ERP.
- Stock Migration Programs: Using specialized programs to upload the final, reconciled stock figures into EWM to match ERP.
- Correction Postings: Making any necessary adjustments in either system to achieve alignment.
- Use /SCWM/ERP_STOCKCHECK: This standard EWM report is invaluable for comparing stock between EWM and ERP and identifying discrepancies. Address any identified differences before proceeding.
4. Release Blocked Deliveries/Documents
- If you blocked new delivery creation in ERP, unblock the relevant shipping points or remove the custom logic.
Phase 5: The Reconnection Process (Step-by-Step)
Once all verification and alignment steps are complete, proceed with the reconnection.
1. Activate Distribution Models (BD64)
- In ERP: Go to and reactivate the distribution models for sending master data and transactional data to EWM.
BD64
2. Enable RFC Communication (SM59)
- In ERP: Restore the correct user and password for the RFC destination pointing to EWM.
- In EWM: Restore the correct user and password for the RFC destination pointing to ERP.
- Test RFC Connection: Verify that the RFC connections are now working correctly.
3. Start Queue Processing (SMQS/SMQR)
- In ERP: Use to register and start the outbound queues sending data to EWM.
SMQS - In EWM: Use to register and start the inbound queues receiving data from ERP.
SMQR
4. Start All EWM-Related Background Jobs
Reactivate all the background jobs that were stopped during the disconnection phase.
5. Unlock EWM Users
Unlock all business users in EWM, allowing them to resume operations.
6. Monitor and Verify Integration
- Monitor Queues (SMQ1/SMQ2): Closely monitor the qRFC queues in both EWM and ERP. Ensure that new messages are flowing correctly and are being processed without errors.
- Monitor IDocs (BD87): Check for any failed IDocs.
BD87 - Test End-to-End Processes:
- Create a new sales order in ERP, and verify that an outbound delivery is created and replicated to EWM. Process it to goods issue.
- Create a purchase order in ERP, and verify that an inbound delivery is created and replicated to EWM. Process it to goods receipt.
- Perform an internal stock movement in EWM and verify updates in ERP.
- User feedback: Gather immediate feedback from key users to identify any integration issues.
Important Considerations and Best Practices
- Dress Rehearsals: Conduct multiple, full-scale dress rehearsals of the entire cutover process, including disconnection and reconnection. This is critical for identifying potential issues and refining the plan.
- Detailed Runbook: Develop a highly detailed, step-by-step cutover runbook. Assign clear responsibilities for each task.
- Fallback Plan: Have a well-defined fallback plan in case of major issues during cutover. This could involve restoring from backups or reverting to the old system.
- Data Archiving/Cleanup: Consider archiving old data in both systems before cutover to reduce migration scope and improve performance.
- Performance Monitoring: Monitor system performance closely during and after cutover to ensure the systems are handling the new load effectively.
- Post-Cutover Support: Provide dedicated hypercare support for the first few days/weeks after cutover to quickly address any arising issues.
- Security: Ensure that only authorized personnel have access to perform these critical disconnection and reconnection steps.
Disconnecting and reconnecting SAP EWM from ERP during cutover is a complex but manageable process with meticulous planning and execution. By following these detailed steps and best practices, you can significantly mitigate risks and ensure a smooth transition to your new SAP landscape.
