Before Brownfield migration to S/4

Introduction

TIME IS MONEY – this is always a valid statement; we believe this is especially valid for SAP ERP upgrade projects (especially SAP ECC to S/4 migration). This blog will provide several key area which can or even need to be anticipated prior starting your S/4 conversion journey – both for greenfield (setup of a new S/4 landscape) or brownfield (upgrade of the existing ECC to S/4)  migration projects.

The main focus of this article is related to Brownfield S/4 migration projects

1) Planning options

A typical timeline of a brownfield upgrade project is about one year, but does this period include also the preparation activities?

Illustration of a Brownfield project plan (without a dedicated preparation period):

This illustration presents the impacts if we plan the preparation activities in advance. The entire brownfield project can be delayed by 6-12 months depending the context.

2) In the following par of this article, we are focusing in more detail on the Brownfield preparation activities.

Functional stream

• As-is and to-be functional process map -  improvement possibilities with S/4 during the brownfield project (Margin analysis, supplier referencing process with BP, etc..)

• Target Application Landscape definition including but not limited to SAP components (ERP, ADS, Content server, Web dispatcher, EWM, BI, PLM, MDM, Cloud services, e-Procurement, S&OP, SAP Add-ons), connected devices as printers, scanners, mobile devices

• Business partner conversion and new GL implementation if appropriate

• Fiori approach including its impact on process design and authorization, FLP vs SAP Gui approach

• BI and reporting approach for S/4

• Simplification item management, obsolete transactions, don’t miss the ACDOCA challenge

IT stream

• IT stream global plan and by sub-streams – SAP basis, IT architecture, security, custom code adaptation, interfaces, data/BI, authorizations, performance

• SAP ECC add-on - check the compatibilities with S/4. Some outdated and non-supported add-ons are extremely difficult to remove. Plan enough time for the add-on preparation.

• Technical Architecture definition - Cloud architecture, sizing and costing, landing zones, high availability/DRP, provisioning, managed services (RISE vs on premise), scale-up during SUM execution

• SAP Readiness check execution, detailed review, recommendations and impact analysis, SDF_HDB_SIZING report run

• Archiving strategy ECC and S/4. Deep archiving in ECC, especially on technical tables - CDCLS (cluster of CDPOS), iDoc (by status), Soffcont1 (workflow, mail attachments). Archiving session sequences (ex archive dedicated objects of CDCLS) review.

• Upgrade preparation –EHP, OS, DB levels, connected devices impact (print server, printers, scanners, mobile devices), DB and Application server upsize during SUM run, disk throughput adaptation, migration and license keys

• Custom code migration  - SCMON log collection, SPDD, SPAU, ATC-UPG strategy, ATC setup and pretests, Quick fix approach, variants and version management

• SAP logon and SAP secure login client strategy, impacts and deployment

• Downtime management, optimization approach and testing options

• Security  - SSO 3.0 impact (Kerberos SAP Gui), SAML2,  integration security (certificates), Cloud security and network security, opening of network flows, admin accesses (domain-based vs local install of S/4), SAP Webdispatcher security design

•  - Integration(interface) strategy including target Middleware architecture and integration patterns (Soap, Rest APIs, IDOC) monitoring (AIF or others), technical activation of interfaces after each refresh and SUM execution, SOA configuration, dry run testing of interfaces, detailed test approach of interfaces in non-prod, dry run and prod instances (smoke tests)

• BI/Data strategy, BW 7.x integration, retired extractors, target data platform, including the S/4 embedded reporting approach

• Performance strategy, approach and tooling, network analysis, action plan with roles and responsibilities in case of issues

Cross stream/Project management

• Overall project plan and approach (blue or brownfield? New S/4 enhancements as opportunity?, pilot or big-bang?)

• Dual maintenance (ECC and S/4 in parallel) – approach, planning, dependencies, risks and securing options

• SAP instance refresh strategy, interface and BW reconnection after refresh and upgrade

• Commercial negotiations with SAP – especially on premise versus RISE license model. New tools (AIF, BTP services, SS0 3.0) to be included and also non-production licenses (example contractual user type for dev, tests, training etc)

• Data migration strategy, tooling and preparation (optional, Blue field)

• Testing strategy, review/update of existing test catalogs and test cases 

• Roles and responsibilities - business, IT, externals, managed services and hosting providers, SAP

• Dry run strategy, including down time optimization, full go live simulations (interface activation, adding additional Application Servers, High availability tests)

• Authorization strategy, matrix, documentation and target compliance, new S/4 authorization cockpit SU25 and new authorization objects management (over 100K new objects), Fiori authorizations and FLP impacts. Remove disactivated authorization objects from existing roles (they will be activated by the merge during SU22c)

• User provisioning approach in non-prod and prod. Assignment of roles and contractual user type ID, etc

• The following chapters will provide more details on above points.

3) Functional stream - some illustration (non-exhaustive)

- As-is and to-be functional process design -  target processes definition, improvement possibilities with S/4. A dedicated project stream should ensure that the current business processes are document including the solution design of the different applications which are part of the business process (ERP, WMS, PLM, e-commerce, e-procurement, etc.). 

The preparation period before the S/4 migration project is an opportunity to analyze improvement possibilities provided by S/4 Hana compared to the existing ERP solution. Even for a Brownfield project, it can be an opportunity to implement functional enhancement. The above schema present the redesign of the supplier management process in a brownfield project. With the Business Partner implementation, the supplier and customer referencing  process needs to be reviewed. This can be an opportunity to onboard new value-added process for the business

Complexity : high  Average duration : 12 months  Start before S/4 migration : 1 year

- Target Application Landscape definition including but not limited to SAP components (ERP, EWM, BI, PLM, MDM, Cloud services, e-Procurement, S&OP, SAP Add-ons).  Based on the target process design it is now possible to start the design of the target application landscape. This should include target SAP and also non-SAP components. This target BOM (bill of material) will be a key input for the license negotiation with software vendors and for the technical infrastructure and security design. The implementation of the target application landscape needs to be planned accordingly to business requirement and the overall portfolio management (please refer to our dedicated blog on this topic)

Complexity : high  Average duration : 6 months  Start before S/4 migration : 1 year

- Business partner (BP) conversion and new GL implementation

This step is a critical activity for Brownfield projects, but also Greenfield projects can take an important benefit of it to cleans client and supplier master data and to prepare them according to the new Business Partner approach.
Based on our experience, this activity can take a significant time (several months). It is important to underline that the brownfield upgrade process (SUM – Software Update Manager) can not be started until all BP related issues are solved. And such it can be a critical showstopper for the entire planning.  Please do it before you engage the upgrade activities and also the Greenfield S/4 project.

Complexity : medium  Average duration : 6 months  Start before S/4 migration : 6-9 months

4) IT stream  - some illustration (non-exhaustive)

- IT stream plan

The high-level IT master plan for the brownfield conversion should start with the preparation phase of the project. It provides a global view on the project and on the different sub-streams. This high-level plan needs to be updated on a regular basis to reflect the real progress of the project. The individual sub-teams (ex technical conversion, integration, etc) can build their more detailed operational plans on it.

Below picture is an illustration only, to this plan we have to add the sub-pans for authorizations, performance, BI/DATA, UI/Fiori.

Complexity : medium  Average duration : ongoing  Start before S/4 migration : 6-9 months

- Technical architecture definition and setup

During the preparation phase the target technical landscape needs to be defined. It should include the security, hosting, sizing of the target S/4 landscape by instance, network architecture and opening of the flow. In case of hyperscaler architecture the landing zone needs to be defined and the dedicated network and sub-nets for S/4 needs to be created.

The landscape should also deal with other components as Content Server, ADS, Cloud connector, Solman/Cloud ALM, Print servers, devices (printers, scanners).

In addition, the ECC and S/4 landscape dependencies need to be defined: refreshes, transports, retrofit/dual maintenance (see illustration below)

Complexity : high  Average duration : 6 months  Start before S/4 migration : 6-9 months

- Custom code adaptations

The custom code adaptation is a very important element for and S/4 brownfield project. Custom codes are impacting both SAP data dictionary (tables, domains, etc) and workbench (programs, badi, etc..). The custom code adaptation can impact a huge number of required adaptation. Before planning the custom code adaptation, we strongly recommend to start as early as possible the scmon trace in your productive instance to collect usage statistics on custom codes. It will be a very important guide to focus the custom code adaptation only on used objects. 

Furthermore, the SPDD and SPAU activities need to be anticipated starting the sandbox and approved by your SAP competency center, as these actions concern SAP standard objects. The ATC need to be setup as early as possible, quick fixes needs to be estimated during sandbox conversion.

Complexity : medium to complex  Average duration : 12 months  Start before S/4 migration : 3-6  months