# SAP Greenfield vs Brownfield Migration Assessment > Source: https://netray.co/tools/sap-greenfield-vs-brownfield-assessment > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Free Tools ## Short answer Ten questions that point toward brownfield conversion, selective data transition or greenfield re-implementation for your S/4HANA move. ## Category sap ## Erp SAP S/4HANA ## Audience - CIO - SAP program manager - SAP architect ## Tool **Kind:** assessment **Questions:** #### How satisfied are business users with how current processes are designed in ECC? **Help:** Satisfied users favour keeping process design (brownfield). Dissatisfied users favour redesign. **Options:** ##### Very dissatisfied, we want a complete redesign **Score:** 0 ##### Several processes need redesign **Score:** 1 ##### Mostly fine with a few improvements wanted **Score:** 2 ##### Processes are sound and well understood **Score:** 3 #### How heavily customised is your ECC system? **Options:** ##### Heavily modified standard with many core changes **Score:** 0 ##### Large Z code base with some modifications **Score:** 1 ##### Moderate custom code, few modifications **Score:** 2 ##### Mostly standard with limited enhancements **Score:** 3 #### What is the quality of your master and transactional data? **Options:** ##### Poor: widespread duplicates and legacy clutter **Score:** 0 ##### Mixed: some areas poor **Score:** 1 ##### Good with known pockets to fix **Score:** 2 ##### Governed and clean **Score:** 3 #### Do you want to change the organisational or financial structure (chart of accounts, company codes, plants)? **Options:** ##### Major restructure planned **Score:** 0 ##### Several structural changes wanted **Score:** 1 ##### Minor changes only **Score:** 2 ##### No structural change **Score:** 3 #### How much historical data must remain in the new system? **Options:** ##### Only open items and balances needed **Score:** 0 ##### One to two years of history **Score:** 1 ##### Several years of history in system **Score:** 2 ##### Full history required in system **Score:** 3 #### How much business disruption can the organisation absorb? **Options:** ##### Large change is acceptable and expected **Score:** 0 ##### Moderate change with strong change management **Score:** 1 ##### Limited change preferred **Score:** 2 ##### Minimal change in how users work **Score:** 3 #### How tight is your timeline and budget? **Options:** ##### Flexible timeline and generous budget **Score:** 0 ##### Moderate flexibility **Score:** 1 ##### Tight timeline or budget **Score:** 2 ##### Fixed deadline tied to end of ECC maintenance **Score:** 3 #### Are you consolidating multiple SAP systems or acquisitions into one? **Options:** ##### Yes, many systems to consolidate **Score:** 0 ##### A few systems to merge **Score:** 1 ##### Maybe one additional system **Score:** 2 ##### No, single system conversion **Score:** 3 #### How much do you want to adopt SAP best-practice content and new capabilities? **Options:** ##### Strongly, adopt standard and retire custom **Score:** 0 ##### Largely, adapt where needed **Score:** 1 ##### Selectively, keep key differentiators **Score:** 2 ##### Little, keep current behaviour **Score:** 3 #### How well do you understand your current ECC configuration and documentation? **Options:** ##### Poorly documented and little knowledge left **Score:** 0 ##### Partly documented **Score:** 1 ##### Reasonably documented **Score:** 2 ##### Well documented and understood **Score:** 3 **Bands:** #### Leans greenfield **Min:** 0 **Max:** 30 **Verdict:** Your answers point to a new implementation: heavy customisation, poor data, structural change or strong desire for process redesign. A greenfield approach lets you adopt standard content and leave legacy complexity behind, at the cost of a larger change effort. **Recommendations:** - Define the target process model and fit-to-standard approach early - Plan data migration and cleansing as a first-class workstream - Invest in change management and training from the start - Decide what historical data to archive versus migrate #### Leans selective or hybrid **Min:** 31 **Max:** 55 **Verdict:** You have mixed signals. A selective data transition, or a phased approach combining conversion for stable areas with redesign for others, may fit. Specialist tooling and partners are often involved, so validate the approach with a proof of concept. **Recommendations:** - List which areas need redesign and which can be converted as is - Evaluate selective data transition tooling and partner experience - Run a sandbox conversion to test feasibility and timing - Compare cost and risk of hybrid against a pure approach #### Leans brownfield **Min:** 56 **Max:** 80 **Verdict:** Your landscape is relatively standard with sound processes and a timeline that favours continuity. A system conversion keeps history and configuration and usually runs faster, though it carries legacy design and data forward. **Recommendations:** - Run Readiness Check and S/4HANA custom code checks - Clean obvious data issues and archive before conversion - Plan for adopting new capabilities after go-live in waves - Rehearse the technical conversion to measure downtime #### Strongly brownfield **Min:** 81 **Max:** 100 **Verdict:** A system conversion is a natural fit: low change appetite, a firm deadline and well-understood configuration. Main risks are custom code remediation, add-ons and testing, rather than redesign. **Recommendations:** - Prioritise custom code usage analysis and remediation - Confirm add-on and interface compatibility - Protect testing capacity and business tester availability - Plan post-conversion optimisation to avoid carrying all legacy forward ## Content **Intro:** The first big S/4HANA decision is how to get there. Greenfield starts clean, brownfield converts your existing system, and selective approaches mix the two. This assessment helps CIOs and program managers see which direction their situation favours before an expensive consulting workshop. **Sections:** #### How to use the assessment **Body:** Answer the ten questions as honestly as you can, ideally with input from both IT and business owners. Each question measures one factor that influences the approach, from process satisfaction and customisation to data quality, structural change, history needs, disruption tolerance, timeline, consolidation, appetite for standard content and documentation quality. The total moves you along a scale from greenfield to brownfield. Treat the result as a hypothesis to validate, not as the final decision. **Bullets:** - Score with both IT and business input - Use the result as a hypothesis - Validate with a sandbox conversion - Record the rationale for the steering committee #### The three approaches in brief **Body:** Brownfield, or system conversion, upgrades the existing ECC system in place to S/4HANA, keeping configuration, history and custom code (subject to remediation). Greenfield implements a new S/4HANA system and migrates selected data, letting you redesign processes and adopt standard content. Selective data transition, sometimes called bluefield, uses specialist tooling to move chosen entities, companies or history into a new or converted system. Each has trade-offs in speed, disruption, cost and clean-up. #### Interpreting the band **Body:** Low scores favour greenfield because the answers indicate redesign appetite, heavy customisation or poor data. High scores favour brownfield because change is unwelcome or time is short. The middle is where most real programs land, and where hybrid choices appear. Consider which answers drive your score: a single factor, such as a mandatory company restructure, can outweigh the rest and change the right approach. #### Common mistakes **Body:** Teams often choose brownfield for speed, and then carry years of poor data and unused code into S/4HANA. Others choose greenfield for a clean slate but underestimate redesign, training and data migration effort. Another trap is deciding before knowing your custom code and data profile. Get the facts from Readiness Check and usage data first. **Cta:** If you want to test your result against your own landscape, we can review your analysis with you and discuss tooling. The assessment is complete without us. **Faq:** #### Which approach is cheapest? **Answer:** There is no universal answer. Brownfield often costs less in project effort for standard landscapes but may carry hidden clean-up costs. Greenfield can cost more upfront and lower the long-term cost of complexity. Compare with your own scope and use a sandbox to firm up estimates. #### Can I move to S/4HANA without disrupting users? **Answer:** Brownfield tends to disrupt less in process terms, though the Fiori user experience, Business Partner and finance changes still affect people. Plan training and communication for every approach. #### What is selective data transition? **Answer:** It is an approach using specialised tools and services to migrate chosen parts of an existing system, such as one company code or recent history, into S/4HANA. It suits carve-outs, mergers and cases where neither pure option fits. #### Does the choice affect RISE? **Answer:** Not directly. RISE is a commercial and operating model, not a migration approach. You can use any of the approaches with RISE or with other hosting options, although some details of the technical path depend on the target environment. ## Search terms greenfield vs brownfield s4hana, sap brownfield or greenfield decision, s4hana migration approach assessment, selective data transition sap, sap system conversion vs new implementation, bluefield s4hana --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json