System tiers

A landscape is the set of systems a change passes through on its way to production, and the rules that govern that path. Its design decides where developers build, where testers prove, where users learn and where business runs. Get it wrong and every test result carries a silent question: was this tested in the right place, with the right code and the right data?

The three-system baseline

The baseline for SAP S/4HANA is a three-system landscape: a development system where configuration and code are created and recorded in transport requests, a quality assurance system where those transports are imported and tested, and a production system where the business runs. Changes flow one way, by transport, from development through quality assurance to production. Nobody configures directly in quality or production. The value of the middle tier depends on one property above all: it must be as close to production as possible, in code, configuration and, as far as privacy allows, data.

Tiers you may add

Larger programs add tiers for specific jobs. A sandbox lets people try things without polluting development, for example a conversion trial or a support package test; changes made there never travel onward. A pre-production system, refreshed from production, carries volume, performance and final integration tests and cutover rehearsals. A training environment, often a client rather than a system, gives users stable data for classes. A second development and quality line lets project work and production support run in parallel; lesson 3 covers that dual track.

Contoso's landscape

Contoso's RISE contract covers CMD, CMQ and CMP. Sam requested two more systems: during the conversion, a sandbox, CMS, built from a copy of ECC production (EP1) and converted first so the team could measure downtime and fix custom code early; and, after go-live, an optional pre-production system, CMR, for performance tests and release rehearsals. The conversion's dress rehearsal itself ran in CMQ, refreshed from production for the purpose. Before choosing, the team checked what the contract included. In the private edition, the number of systems depends on the RISE contract, and extra tiers cost money every month.

Public edition tiers

In SAP S/4HANA Cloud Public Edition, SAP provisions the systems. Since release 2208 customers can have a three-system landscape of development, test and production, with SAP Central Business Configuration connected to development and changes moved in sequence through transport requests and software collections; older customers may still run a two-system landscape of quality and production. A starter system with sample data supports fit-to-standard workshops and can be decommissioned later. The architect cannot add a pre-production tier there, so production-like testing happens in the test system.

Write it down

A landscape that lives only in Sam's head is a risk. Contoso keeps one landscape diagram, owned by the architect and updated with every change: systems and their purpose, clients and their roles, BTP subaccounts and the ERP tier each one points to, transport routes, refresh schedule and who approves imports at each step. Testers use it to put the system and client in every test case header and every defect, and auditors use it to see that production receives only approved, tested changes. When the diagram and reality disagree, the diagram is fixed the same day.