When legacy systems work—but can’t continue

A major research publisher faced a familiar enterprise dilemma. Its Author Services business ran entirely on AS/400, supported by more than 30 years of accumulated custom code.

The system worked, but at a growing cost. Operating expenses were high. Specialized talent was increasingly scarce. And the platform could not meet modern availability expectations.

Yet the custom logic wasn’t optional. It supported highly specialized academic publishing workflows, including:

• Complex quoting with multi-tiered discount waterfalls (~1M pricing records)

• Institutional contract management across 8,000+ institutions and hundreds of consortia

• Prepaid and postpaid funding models

• Multi-author, multi-institution, multi-payer scenarios

• Split payments across currencies and tax jurisdictions

The business needed to modernize—but without abandoning what made it work.

The false choice between recreation and abandonment

As the company planned its move to SAP ECC (and eventually S/4HANA), it was presented with two unappealing options.

They could recreate 30 years of bespoke logic inside SAP, resulting in:

• A massive, multi-year development effort

• Heavy ECC customizations

• Complex pricing, contracts, and funding logic embedded in ERP

• A bloated system that would make future S/4 migration equally painful

Or they could abandon their custom processes and force the business to conform to standard ERP workflows—losing optimized publishing models and competitive differentiation.

Neither path made sense. Recreating legacy complexity in a modern ERP would only move the problem forward.

A third path: extract, modernize, simplify ERP

Instead of migrating custom code into SAP, the publisher extracted all Author Services business logic into viax and implemented SAP ECC as a clean, vanilla backbone.

This approach enabled them to:

• Fully decommission AS/400

• Preserve and modernize complex business logic outside ERP

• Implement ECC with only standard order management, fulfillment, and revenue recognition

• Establish a dramatically simpler path to S/4HANA

The result was not just a system migration, but a structural reset. ERP stopped being the place where bespoke logic lived.

Separating business logic from the ERP backbone

With this architecture, responsibilities were clearly divided.

viax handled business logic, including:

• Complex quoting and discount waterfalls

• Institutional contract management

• Prepaid and postpaid funding models

• Multi-party allocation across authors and institutions

• Real-time funds availability checks

• ~1M pricing and discount records

SAP ECC handled the backbone, including:

• Standard order management

• Fulfillment

• Revenue recognition

• No customizations

Customer-facing systems interacted with viax APIs, which orchestrated workflows and passed clean orders into ECC. ERP remained stable and simple.

Preserving complexity while improving performance

Extracting business logic didn’t just preserve capabilities—it improved them.

Pricing calculations that once depended on ERP calls were now executed entirely within viax. Complex discount stacks were applied in real time, independent of ERP availability.

This enabled:

• 24/7/365 pricing availability

• Real-time responses even during ERP downtime

• Reduced ERP load

• Fully automated order processing from submission through publication

Multi-party funding scenarios—such as multiple authors across regions with different funding sources—were handled cleanly and consistently, without manual intervention.

A cleaner migration path forward

The architectural impact extended well beyond the initial AS/400 exit.

Without viax, the migration path would have been:

• AS/400 custom logic recreated in ECC

• ECC bloated with bespoke logic

• Customized ECC migrated to S/4

• S/4 inheriting decades of complexity

With viax, the path became:

• AS/400 custom logic extracted and modernized

• ECC implemented as vanilla only

• AS/400 decommissioned

• Future ECC → S/4 migration limited to standard processes

As the publisher put it, the S/4 migration became “many, many multiple times easier.”

Why this pattern matters

Legacy custom code does not need to be recreated inside modern ERP. Separating concerns changes the equation.

Business-specific logic belongs in platforms designed to evolve. ERP should handle standard processes reliably and predictably.

This publisher decommissioned AS/400, reduced operating costs, automated workflows, improved performance, and set up a clean S/4HANA path—all while enhancing core business capabilities.

That’s not lift-and-shift.
That’s strategic modernization.