How do you plan to eat your S/4HANA elephant?

S/4HANA Greenfield transformation vs. Brownfield transformation: implications for test approach.

January 20, 2021

Evgeniia Antonova SAP

The book time

Thanks to two executive IT Architects - R. Hopkins and K. Jenkins and their book “Eating the IT Elephant”, nowadays we are talking often about Greenfield, Brownfield, and x-field approaches not only in terms of construction but in software development as well.

One of those hot topics in software world lately is S/4HANA transformation and the ways of dealing with the testing in such projects. So, there are three common approaches for S/4HANA transformation distinguished:
Greenfield scenario, meaning a new SAP implementation from scratch.
Brownfield scenario describes system conversion when the existing SAP ERP system is transformed to S/4HANA in phases.
X-field scenario can be named differently but generally tries to combine to some extend both approaches above.

Which color to go?

The decision which scenario to apply is a company-specific and should consider unique company circumstances, but there is a classical set of high-level recommendations:
Go Greenfield way when:
• Re-design & re-engineering of current business processes are desired 
• Major revision of custom code & obsolete interfaces are required
But be ready to: 
• Map the business process to the standard S/4HANA and define gap for customization 
• Conduct risk assessment for defined new requirements 
• Review & transform the master data 
• Re-integrate with 3rd party systems
The significant advantage for such cases is the availability of industry preconfigured solutions on the market which potentially can accelerate the S/4HANA transformation and spare company resources.
Go Brownfield way when: 
• The current SAP system is close to standard 
• There are no legacy issues 
• Master data is of high quality 
• Gradual approach leveraging S/4HANA functions is desired
But be ready to: 
• Conduct deep analysis of existing customizations to define gaps to S/4HANA standard 
• Map & transform data to fit new database structure 
• Integrate with legacy systems & interfaces

Is test approach colorblind?

Looking from the test perspective, though, it doesn´t matter whether one is going to eat an elephant in greenfield or brownfield, one still proceeds bite by bite.

So, the aspects to be taken into consideration by test planning for S/4HANA project are independent from the chosen transformation scenario and defined more by company specifics & industry quality standards. To avoid the cliché of the test being a bottleneck consuming 30-40% of the average IT budget, the chosen test approach should cover at least following topics: 
• Proper requirements risk assessment in early stages, incl. impact analysis for non-SAP and legacy SAP systems 
• Extensive E2E testing of business processes, incl. non- SAP systems integration 
• Planning sufficient regression testing cycles, incl. optimal level of test automation 
• Representative test data identification & data constellation testing in E2E processes 
• Role-based & authorization testing 
• Reports testing, incl. BI-reports 
• Performance testing 
• Testing on multiple supported devices

Conclusion

Today we found out that the chosen transformation strategy doesn´t necessarily affect the test approach and in that sense S/4HANA test approach would be color-blind.

We are SAP-elephant-friendly company.