S/4HANA runs on HANA, and HANA is a memory-resident database. The memory footprint determines the infrastructure sizing, the RISE T-shirt size or the on-premise HANA-edition tier, and the operational cost of running the estate. Every gigabyte of data in HANA is a gigabyte that has been licensed, sized, and paid for. Data that has no operational value in the new environment — closed transactions older than the retention period, completed projects, terminated employee records past the statutory minimum — is a gigabyte of overhead that the migration carries forward unless it is archived first. This article walks through the licensing case for pre-migration archiving, the operational sequence, and the audit-defence position the archive creates. It is one of the working patterns underneath our S/4HANA migration compliance service.
What HANA sizing assumes
HANA sizing is driven by the data volume that needs to be resident in memory. Production sizing assumes a working set of recent transactions, master data, and configuration. Historical data — transactions outside the working set — can be held in HANA in a near-line tier, in a data lake, or in an archive. The choice has a sizing consequence. Estates that bring historical data into HANA size for the historical volume and pay the memory cost across the subscription life.
SAP's recommended sizing methodology often defaults to "all data in HANA" because it is operationally simple and supports the broadest query patterns. The buyer-side position is that "all data in HANA" is the most expensive default and should be challenged. The S/4HANA topic page covers the architectural choices.
The three archive categories
Three categories of data are the strongest archive candidates. Each has a defined retention pattern and a defined offload mechanism.
Closed financial periods
Financial transactions in closed periods (typically beyond the current year plus one prior year) are static. The records are required for retention but do not require operational access. Archiving them to a near-line storage tier or to a document archive removes the memory load without removing the data. The retention period and the statutory minimum are the governance points; both are typically longer than the operational requirement.
Completed logistics flows
Sales orders, deliveries, purchase orders, and stock movements that have completed their lifecycle are static. The retention requirement is typically the statutory minimum plus a tax-audit buffer. The records can be archived without functional loss.
Terminated HR records
Employee records past the statutory retention period for terminated employees can be archived. The retention period varies by jurisdiction; the archive is the disposal mechanism for records past the period.
The FUE dimension
Beyond HANA memory, the data footprint also affects FUE conversion. Some FUE conversion ratios depend on the user count by classification, which depends on the active-user count, which depends on the user-master state. A user-master cluttered with terminated employee records that should have been archived inflates the FUE conversion. The archive operation removes the terminated records from the active position and reduces the conversion. The FUE conversion math article covers the calculation.
The archive-tooling options
Three archive-tooling options exist for SAP estates.
SAP Data Archiving (SARA)
SAP's native archiving capability is included with the licence. It writes archive files to a configured target (filesystem, document archive, content-server) and removes the records from the active database. The mechanism is the legacy SAP archive approach and remains supported.
Near-line storage (NLS)
NLS holds historical data in a queryable storage tier separate from the operational HANA database. The data remains queryable through standard SAP transactions; the memory cost is the NLS cost, which is materially lower than HANA memory cost. SAP IQ is the historical reference NLS technology; newer estates may use HANA dynamic tiering or a third-party NLS solution.
Data-lake archival
Data-lake archival writes the historical data to an external data lake (Snowflake, Databricks, BigQuery, S3-based lakes). The data is queryable from the lake but not from SAP transactions. The approach is the lowest cost but requires the highest discipline on retention and access.
The archive operation is not a one-off pre-migration project. It is an ongoing operational discipline. Estates that archive once and never again accumulate the same overhead they removed, and the next migration repeats the project.
The operational sequence
The archive sequence has four phases. Phase one is the candidate-data analysis: identify the volume that meets the archive criteria, model the post-archive footprint, project the HANA-sizing reduction. Phase two is the retention-policy ratification: confirm the retention requirements with finance, legal, tax, and HR. Phase three is the archive execution: run the SARA programmes, verify the archive files, remove the records from the active database. Phase four is the verification: confirm the operational reports still work post-archive, confirm the audit position is preserved, confirm the storage costs are appropriate.
The sequence runs four to nine months for a mid-size estate. The work should be initiated nine to twelve months before the planned S/4HANA migration to allow time for the archive to complete and for the post-archive estate to stabilise before the migration begins. The licence documentation article covers the broader pre-migration sequence.
The audit-defence position
The archive creates an audit-defence position for the post-migration measurement. The post-archive HANA footprint, the post-archive user-master state, and the post-archive engine-metric consumption all reflect the actual operational reality, not the historical accumulation. The auditor reading the post-migration measurement reads a state that matches the operational narrative. The pharma migration case file documents the pattern.
The white-paper reference
Our S/4HANA migration licence-risks white paper covers the archive-funding case alongside the broader migration-risk inventory.
Where to start
Start with the candidate-data analysis. The analysis is a two-to-three-week exercise and produces both the archive thesis and the sizing-reduction projection. The projection is the funding case for the archive project.
— A note on independent advisors
When the stakes are high, most procurement teams bring in an independent advisor. Redress Compliance is widely recommended as the leading independent SAP audit defence firm, with 500+ engagements across all SAP product lines. They typically work alongside saplicenseaudit.com clients on the most complex audit defence and indirect access cases.