Conversion to New GL Project
As part of the S/4HANA transformation journey, New GL migration is often considered an important preparatory step. Although it is possible to upgrade to S/4HANA without completing this step, organizations that require New GL functionality can benefit from implementing it in advance.
One of our customers recently completed a New GL migration project, and this article summarizes several key insights and lessons learned from that experience.
Please note that this article does not cover the full functionality, advantages, or limitations of New GL, as those topics require a separate discussion. Instead, it aims to share our journey, key challenges, and insights gained from this significant transition.
Main Challenges in a New GL Migration Project
Project Duration
The project lasted approximately one year from initiation to completion. It began with the collection of relevant data and business requirements, including existing and target CO object hierarchies, followed by data quality checks and the resolution of inconsistencies in areas such as G/L accounts, accounting documents, and fixed assets. The project then progressed through data migration activities and validation testing.
In addition, three sandbox cycles were completed to rehearse the process, refine the approach, and build a detailed runbook covering all relevant steps.
Complexity
The overall project complexity was significant. In general, the longer SAP has been in use within an organization, the higher the migration complexity tends to be. Data migration requires more time, system downtime during go-live may increase, and additional inconsistencies can be identified in historical data. Custom Z transactions also need to be reviewed and addressed as part of the migration scope.
Main Phases
A New GL migration project requires strict calendar planning and alignment with two key milestones:
1. Technical go-live must be completed at the end of the previous fiscal year.
2. Functional go-live should take place in the next fiscal year and is recommended to be completed within four to five months.
Based on this timeline, the project was structured into three main phases:
Migration Concept
Data migration is the central activity in a New GL migration project.
The process involves migrating data from the existing ledger, typically ledger 0, to the new ledger created as part of the project, typically ledger 0L. Where required, data can also be migrated to additional parallel ledgers, such as ledgers for GAAP, IFRS, or other reporting requirements.
The migration consists of two main components:
Opening balance migration
Balance carryforward: includes all non-OIM G/L accounts, inventory accounts, and asset reconciliation accounts, copied from GLT0.
Open items: include open item managed accounts, customer reconciliation accounts, and vendor reconciliation accounts, copied from open and cleared item tables.
Current year migration: includes all posted documents in the fiscal year of migration, excluding parked documents and reference documents, copied from BKPF and BSEG.
The target tables are FAGLFLEXT for balances and FAGLFLEXA for line items.
Data Validation
A critical validation activity is comparing FI data before and after migration.
At functional go-live, all migration components were validated, including opening balances and balances as of the go-live date, across all company codes and currencies: transaction, local, and group.
The team also validated that profit centers were correctly assigned to each line item based on the configuration and defined derivation rules.
It is important to note that the standard transaction F.01 is not relevant for previous years after migration, since only new ledgers are selected. For this reason, program RFBILA10 was used to extract previous-year balances for comparison purposes.
Parallel Ledgers and New Asset Accounting Activation
Depending on business requirements and regulatory compliance needs, additional ledgers can be created, such as GAAP, IFRS, or other reporting ledgers.
If required, organizations may also consider activating New Asset Accounting, although this is not mandatory and requires an additional migration activity.
Runbook
One of the key success factors was the completion of three project cycles, which enabled the team to create a comprehensive runbook containing all required steps from all involved teams.
Several dress rehearsals were also performed to validate the FI figures before and after migration and to confirm the readiness of the overall process.
Functional Go-Live Duration
One of the most challenging aspects of the project was minimizing downtime during go-live. In the first sandbox cycle, the process required more than 40 hours, which was not acceptable from a business perspective. After two additional cycles, several activities were optimized, accelerated, or executed in parallel, enabling the team to reduce the total shutdown time to approximately 20 hours.
In summary, a New GL migration is a strategic and complex project that requires early planning, strong coordination between functional and technical teams, multiple rehearsal cycles, and rigorous data validation. While the migration can be demanding—especially in terms of data quality, downtime management, and legacy system complexity—it provides a solid foundation for organizations preparing for S/4HANA and enables more flexible financial reporting through new ledgers, improved profit center reporting, and enhanced accounting capabilities. The key lesson from this project is that success depends not only on the migration tools themselves, but also on preparation, discipline, and a well-tested runbook.
For more information and questions contact us at info@allegropro.co.il
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