What's included
A conversion is not a project that ends at go-live, it ends when the freeze window closes and the books reconcile. The bars below put the mock cutovers and the freeze where they actually sit:
- Path decision & readiness, Readiness check reports, simplification item analysis, the brownfield versus greenfield decision itself, sizing, and the target landscape design. Milestone: conversion path signed off.
- Preparation & custom code remediation, The part of a conversion nobody sizes correctly: custom code analysis against the simplification database, remediation waves, obsolete code retirement, and the finance data model preparation the conversion depends on. Milestone: custom code remediation complete.
- Sandbox & development conversion, The first technical conversion on a sandbox copy, the runtime it reveals, then the development and quality systems, with functional adaptation and unit testing behind each. Milestone: quality system converted.
- Test cycles, Functional, integration, interface, authorisation and performance testing, plus the defect loop, running against a converted quality system rather than a greenfield build. Milestone: integration test exit passed.
- Mock cutovers & dress rehearsal, Three mock cutovers on full production data volumes, each measured and each shortening the runbook, then the dress rehearsal that gates go/no-go. Milestone: dress rehearsal go/no-go decision.
- Freeze, cutover & hypercare, The business freeze window, the production conversion itself, validation and reconciliation, release to business, and the hypercare period before support hands back. Milestone: hypercare exit.
Who uses this template
SAP programme managers, ERP consultants, and IT transformation leads use this to run a S/4HANA move. It lays out a brownfield conversion path with custom-code remediation, multiple mock cutovers, a dress rehearsal, the go/no-go decision, and the business freeze, so a high-risk migration lands cleanly over a single controlled weekend.
How to customize it
- If you are doing a new implementation rather than a conversion, delete the remediation and mock cutover phases and rebuild around process design, the shapes are genuinely different.
- Set the production cutover weekend first and count backwards; the mock cutovers are the only reliable estimate of how long it takes.
- Split custom code remediation into waves by object owner, not by object count, so the bars match who actually does the work.
- Lengthen the freeze window if you have high transaction volumes at period end, and avoid running the cutover across a fiscal period boundary.
- Add rows for each interface and satellite system, conversions usually break integrations before they break SAP itself.
- Add a fourth mock cutover if the third one has not yet finished inside the available window.
Scheduling tips
- Run mock cutover one early and badly. Its job is to find out what is missing from the runbook, not to succeed. Later mocks are the ones that need to look clean.
- Triage the readiness report, do not count it. A thousand findings can be two weeks of work or six months, and only triage tells you which.
- Treat the dress rehearsal as a real gate. If the rehearsal cannot finish inside the planned window, the production cutover will not either, that is the entire point of running it.
- Freeze the business, not just the system. Publish what people can and cannot do each day of the window, well before it starts.
- Reconcile before you release. Financial balances, open items and stock quantities validated against pre-conversion figures is the actual go-live criterion, not a green screen.
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Frequently asked questions
How long does an SAP S/4HANA migration take?
A system conversion commonly runs twelve to twenty months depending on custom code volume and the number of interfaces. The template uses roughly sixteen months. New implementations vary far more widely because the schedule is driven by process design rather than by remediation.
What is the difference between brownfield and greenfield?
Brownfield is a system conversion: you keep your existing configuration, history and custom code, and convert the system in place. Greenfield is a new implementation you migrate selected data into. Brownfield schedules are dominated by custom code remediation and mock cutovers; greenfield schedules are dominated by process design and change management. This template shows the brownfield path.
How is this different from the ERP implementation schedule?
The ERP implementation schedule assumes you are selecting and implementing a system from scratch, vendor selection, process design, configuration, data migration and training. This plan assumes SAP is already running and you are converting it, so the heavy phases are custom code remediation and repeated mock cutovers instead.
How many mock cutovers do I need?
Three is the usual planning number and the template uses three, followed by a dress rehearsal. Each one runs the full runbook on production data volumes and is timed; if the third still overruns the available window, add a fourth rather than compressing the real one.
How long should the business freeze be?
Longer than the technical cutover. Postings, master data changes and open transaction closure typically freeze several days before the conversion starts and stay frozen until reconciliation passes. Use your mock cutover timings to size it rather than guessing, and communicate it to the business weeks in advance.
Is the SAP S/4HANA template free?
Yes. Free Excel, PowerPoint and CSV downloads, and free online editing with no account and no watermark.