Skip to main content
Schedule Call With Us
SAP Migration

Move Off SAP ECC to S/4HANA on a Date You Choose

Mainstream maintenance for SAP ECC ends in 2027, so the question is no longer whether you move but how. We execute all three routes, run the readiness check first, and size the downtime window before you commit to a cutover weekend.

50+ ERP and software projects. Zero failed projects since 2021.

Book a Free Consultation → Features
Conversion Route
Illustrative
Chosen after the readiness check, not before
✓
System conversion, brownfield
Keeps history, configuration and open documents. Costs you the custom code remediation.
○
New implementation, greenfield
Clean configuration and standard processes. Costs you a full rebuild and retraining.
○
Selective data transition
Keeps chosen company codes or a set history window. Costs more in tooling and planning.
Sandbox conversion in 4 to 8 weeks proves the route before the programme is priced.
4-8 wk
Sandbox conversion
9-15 mo
Full conversion programme
2+
Dress rehearsals before production
0
Failed projects since 2021
Why It Matters

The 2027 deadline is a capacity problem, not just a date

Every SAP customer on ECC is queuing for the same conversion skills in the same two years. The systems that start late pay more for less experienced teams.

Custom Code Is the Budget

Most of your custom objects should be retired, not remediated

A typical ECC system carries thousands of Z objects, and the usage evidence usually shows that well over half have not run in years. Remediating a dead report against the simplification database costs the same as remediating a live one. We measure what actually executes with the ABAP Call Monitor first, then fix only what survives.

  • Custom code analysed against the SAP simplification database.
  • Runtime usage data used to build a retirement list.
  • Remediation effort quoted per object, not as a lump sum.
Reviewing custom ABAP code findings before an S/4HANA conversion
Downtime You Can Plan Around

A weekend window, proven twice before the real run

The technical conversion runs through SUM with the Database Migration Option, and the honest answer on business downtime is 30 to 50 hours for a normal system. Downtime-optimised approaches can pull a large system under 24 hours. We rehearse the full runbook at least twice on production-sized data, so the number you are given is measured rather than estimated.

  • SUM with DMO, timed on a copy of production data.
  • At least two dress rehearsals with the full cutover runbook.
  • A posting freeze and rollback point agreed with finance.
Planning the cutover downtime window for an SAP S/4HANA migration
What Moves Across

The objects and artefacts we migrate

Each one behaves differently in a conversion. These are the six that decide your timeline and your testing effort.

👤
Master data
Customers and vendors converted to the Business Partner model through Customer Vendor Integration, plus material masters affected by the 40 character field length change.
📜
Open transactional documents
Sales orders, purchase orders, deliveries, open items in AR and AP and work in progress, all cleared or carried according to a rule agreed per document type.
📚
Historical documents
Closed documents convert in place in a brownfield run. In a greenfield or selective run you pick a history window and keep the rest read-only or archived.
💰
Financial balances
FI and CO merge into the Universal Journal, table ACDOCA. Ledgers, currencies and document splitting are prepared first, then every balance is reconciled after conversion.
⚙
Custom code and developments
Z reports, enhancements, user exits and BAdIs checked against the simplification database, then retired, remediated or rewritten based on real usage evidence.
📡
Interfaces and output forms
IDoc and RFC connections, PI and Integration Suite flows, plus SAPscript and Smart Forms output that has to be retested against the converted tables.
How It Works

Five stages from readiness check to production cutover

1
Readiness check
SAP Readiness Check on the live system, simplification items reviewed and the route decided.
2
Sandbox conversion
A real conversion on a copy in 4 to 8 weeks, which produces the true effort and timing.
3
Preparation
Business Partner and CVI work, finance preparation for ACDOCA, custom code remediation.
4
Dress rehearsals
Two or more timed runs of the full runbook on production data, with the window measured.
5
Production cutover
A weekend freeze, the SUM run, reconciliation, then hypercare through the first close.
What Is Included

What the migration covers

📋

Readiness check report

The SAP Readiness Check output read back to you in plain terms, with the blockers separated from the noise.

🔍

Simplification item analysis

Every relevant simplification item assessed against your configuration, with the consistency checks run and cleared.

⚙

Custom code remediation

A retirement list built from usage data, then fixes for the objects that stay, tested in the converted sandbox.

🔄

Business Partner and CVI

Number ranges, groupings and the Customer Vendor Integration mapping, run and reconciled before the technical conversion.

📊

Migration Cockpit loads

Greenfield and selective data loads built in the SAP S/4HANA Migration Cockpit, repeatable and reconciled per object.

📅

Cutover runbook

A timed task list with owners, the posting freeze, the SUM sequence, validation checks and the rollback point.

What Changes

What you get out of the conversion

One
Universal Journal for FI and CO
Weekend
Measured cutover window
Fewer
Custom objects to maintain
Faster
Period close and reporting
Clean
Business Partner master data
Past
The 2027 maintenance deadline
Why Us

Why teams choose TCB Infotech to run the conversion

1
We execute all three routes
Brownfield, greenfield and selective data transition, so the recommendation is not driven by what we can deliver.
2
Sandbox before the price
A real conversion on a copy gives the effort number. Quoting a programme without one is guesswork.
3
We push you to retire code
Deleting an unused Z report is cheaper than remediating it, and we bring the usage evidence to prove which is which.
4
Honest on downtime
A measured weekend window with a rollback point beats a zero downtime claim that falls apart on the night.
5
Finance in the room early
ACDOCA, ledgers and currency setup are decided with your controllers, not retrofitted after conversion.
6
Proven delivery
50+ ERP and software projects across industries, with zero failed projects since 2021.
FAQ

SAP migration questions

How long does an ECC to S/4HANA conversion take?
A sandbox conversion takes 4 to 8 weeks and tells you what you are actually dealing with. A full programme through sandbox, development, quality and production usually runs 9 to 15 months for a single production system, and longer if you are consolidating several. Custom code volume and the state of your finance data move that number far more than user count does.
Should we do a system conversion or a new implementation?
If your configuration still fits the business and you want to keep history and open documents, a system conversion is the cheaper and faster route. If your ECC carries 15 years of workarounds nobody can explain, a new implementation costs more up front and saves you from rebuilding the mess in a new database. Selective data transition sits between the two and suits groups that only want certain company codes carried across.
How much downtime should we plan for the production cutover?
Plan for a weekend. A production run using SUM with the Database Migration Option typically takes 30 to 50 hours of business downtime, and downtime-optimised options can bring a large system under 24 hours. We do not promise zero downtime, because nobody delivers it. We shorten the window with at least two dress rehearsals and agree the posting freeze with finance in advance.
What happens to our custom code?
It is analysed against the SAP simplification database before anything is touched. On most ECC systems more than half the custom objects have not been executed in years, and retiring them is far cheaper than remediating them. We use runtime evidence from the ABAP Call Monitor and Usage Procedure Logging to separate live code from dead code, then fix only what survives that cut.
Does our historical data come across?
In a system conversion, yes. Documents, balances and configuration convert in place, and financial history lands in the Universal Journal table ACDOCA. In a new implementation you re-migrate what you choose, normally masters, open items and opening balances, with older records kept read-only in ECC or in an archive. Selective data transition lets you pick a history window, such as the last two fiscal years.
What does the SAP Readiness Check tell us?
It runs against your live ECC system and returns the simplification items that apply to you, custom code findings, the add-ons and business functions that block a conversion, a data volume profile and a sizing estimate for S/4HANA. It is the cheapest way to get a real scope, and we run it in the first two weeks, before anyone quotes a fixed price.

Plan Your Move Off SAP ECC

Book a free consultation. Tell us your ECC release, database and rough custom code volume, and we will walk through which route fits, what the sandbox conversion would show, and how the cutover weekend would be sequenced.

Book a Free Consultation →

No commitment. A practical first look at your S/4HANA conversion.

SAP Migration Features

What Is Inside an ECC to S/4HANA Migration

A conversion is a technical programme with a hard finance deadline attached to it. Here is how we pick the route, what we clean up before the SUM run, how the downtime gets measured, and what you hold at the end.

Core Features

From readiness check to a cutover weekend that holds

Readiness and Route

The sandbox conversion decides the plan, not a workshop

We run the SAP Readiness Check against your live ECC system, then convert a full copy in a sandbox within 4 to 8 weeks. That run surfaces the blocking add-ons, the active business functions, the simplification items you actually hit and the real runtime. Only then do we recommend system conversion, new implementation or selective data transition.

  • Readiness Check run in the first two weeks.
  • Simplification item list assessed against your configuration.
  • Route recommended on measured evidence, including when greenfield is the cheaper answer.
Reviewing SAP Readiness Check findings to choose a conversion route
Preparation and Remediation

The mandatory clean-up that happens before the conversion

Customers and vendors have to become Business Partners through Customer Vendor Integration, and that work is done in ECC before the technical run. Finance is prepared for the Universal Journal so FI and CO land in ACDOCA correctly. Material number field length changes are checked against your interfaces, and custom code is retired or remediated against the simplification database.

  • Business Partner number ranges, groupings and CVI mapping.
  • Ledger, currency and document splitting prepared for ACDOCA.
  • Custom objects retired on usage evidence before anyone pays to fix them.
Preparing financial data for the Universal Journal before an S/4HANA conversion
Rehearsal and Cutover

Two timed rehearsals before anyone freezes postings

The technical conversion runs through SUM with the Database Migration Option, and we time it on production-sized data at least twice. Each rehearsal ends with the same validation pack your finance team will run for real. By the production weekend the window is a measured number with an agreed rollback point, not a promise.

  • Full runbook rehearsed with owners and timings per task.
  • Downtime-optimised options assessed where the window is tight.
  • Hypercare through the first period close after go-live.
Project team running a cutover dress rehearsal for an SAP migration
What You Get

Everything the migration delivers

📋

Readiness and scope pack

Readiness Check findings, blocking add-ons, sizing estimate and the recommended route, written down.

⚙

Converted sandbox system

A working S/4HANA copy of your business, with measured runtimes and a real list of defects to close.

🔍

Custom code register

Every Z object classified as retire, remediate or rewrite, with the usage evidence behind each decision.

🔄

Data preparation record

Business Partner and CVI results, finance preparation steps and the reconciliation behind each object.

📅

Timed cutover runbook

Task by task with owners, durations from the rehearsals, validation checks and the rollback point.

📚

Handover documentation

Configuration notes, tested interfaces and support runbooks, so your team is not dependent on us.