S/4HANA Migration: What Data Preparation Really Costs When You Do It Yourself

Every S/4HANA project starts the same way — until someone asks for clean master data

Every ECC-to-S/4HANA project begins with a partner, a plan and a go-live date. Somewhere around the first or second workshop the client hears a sentence that is never in the proposal: you will need to supply clean master data.

The Business Partner conversion — merging customers and vendors into one BP model with roles, groupings and categories — is rarely listed as a deliverable. It lands on the client’s own team, and on a mid-sized landscape it can exceed the implementation partner’s effort for the whole module.

Let’s count what it costs if you do it yourself

Take a realistic case: about 100,000 customer and vendor records across two or three company codes. Done by hand, with queries, spreadsheets and e-mail, the stages look like this:

Stage	What it involves by hand	Typical effort
Current-state profiling	Analysis, queries, data-quality reports	60–120 h
Deduplication logic	Building rules, verification, repeated iterations	80–160 h
Mapping to the BP structure	Roles, partner functions, categories — all manual	120–240 h
Validation rules	Writing, implementing, testing	80–160 h
Business validation (e-mail + Excel)	Coordination, merging versions, finding the current copy	100–200 h
Load attempts	Test loads, error analysis	150–300 h
Rework and fixes	Repeated loops until the load passes	100–200+ h
Total		800–1,000+ h

Assume €50–80 per internal specialist hour (adjust to your own rates): that is €40,000–80,000 of internal time alone. At typical external consultant rates of €120–150 per hour, the same work runs into the hundreds of thousands. And the hours are not the whole bill.

Business pulled off its real work

Finance, procurement and sales people end up managing spreadsheets instead of doing the jobs the organisation pays them for. The capacity that should be generating value is merging duplicate vendor records.

Trial and error under pressure

Errors surface weeks before cut-over, when the plan has no slack left. Every late discovery forces a rushed fix at the worst possible moment.

Risk of a slipped go-live

A missed date is the most expensive outcome of all — and data problems are among its most frequent causes.

After roughly 1,000 hours you have one-off clean data. You do not have a repeatable standard, and you do not have a tool to keep the data clean when the next partner, the next wave or the next operating company comes along.

How we do it — at a fixed price

We have run this work for more than sixteen years. The templates, the tested algorithms and our own tooling — vise DMW — are what let us offer a fixed, predictable price instead of an open-ended engagement. The work runs as a pipeline where each step is a gate that removes one class of error before the next:

SAP ECC → 01 Extraction and profiling → 02 Deduplication → 03 Mapping and harmonisation → 04 Validation rules → 05 Load simulation → S/4HANA

01 · Pull only what truly goes to S/4

Scope criteria are agreed together: active partners, open items, transactions from an agreed period. The full legacy database is not migrated by default.

02 · A real picture of your data

Profiling shows completeness gaps, empty fields, inconsistent value lists and problematic records — before the load, not during it.

03 · Deduplication by agreed algorithms, not magic

Duplicates are merged under rules agreed with you. The process is transparent and reviewable: you can see why two records were treated as one.

04 · FieldMap + vise LoV-MAP

vise FieldMap drafts the mapping of customer and vendor data to the Business Partner structure and flags the errors that would take weeks to find by hand; your consultant approves every line. vise LoV-MAP harmonises dictionaries and values across companies — payment terms, account groups, countries, reconciliation accounts — so multi-OpCo data stays consistent.

05 · Validation rules — not just SAP’s

Standard SAP checks cover formats and mandatory fields. The expensive errors come from business logic SAP does not know — an account that must sit in a particular reconciliation group only for a given customer account group, for example. You document those rules in Word, Excel, PDF or whatever is convenient; we implement them as validations. You define what correct data means; we confirm every record meets it.

Load simulation: prove the data will pass — before you load anything

A full load simulation runs against the chosen target — Quality, pre-production, any system — through the same standard interfaces the real load uses, without writing a single record. It shows whether the data will pass and surfaces the errors before anything reaches production. Simulations start well before cut-over and are repeated for each target as often as needed.

What you get at the end — and what we commit to

The scope is fixed and agreed up front. You choose how the data arrives:

• Loaded for you. Our tooling posts the validated data into S/4HANA through BAPI, IDoc or OData — the same engine that ran the simulations, now writing for real. Never a direct table write.
• Or handed over, ready. Prefer to load it yourselves or through your implementation partner? You receive it in SAP Migration Cockpit format, pre-validated so the upload has no surprises.

Beyond the data itself you keep a standard and a tool for maintaining data quality with future partners, waves and operating companies — a repeatable, fixed-price service rather than a one-time clean-up.

Compare it for yourself

Do it yourself	With Visehub
800–1,000+ hours of internal time	Predictable, fixed price
Trial and error under go-live pressure	A team that has done this in production since 2017
Standing risk of a missed date	A standard you keep
Clean data for one-time use	A repeatable process for future partners

We have done this on a long-standing programme for a global brewing group operating across many markets, and for mid-sized companies moving between SAP and Microsoft Dynamics. The pipeline is the same; only the objects change.

Planning a move to S/4HANA?

If you have not yet decided who will prepare your data, start with a free 30-minute data-readiness assessment — no obligation — or bring one object to a 30-day proof of concept. You see the scorecard, the mapping and the load simulation on your own data before committing to anything.