System landscape design - Excerpt from The Essential SAP Career Guide

Excerpt from The Essential SAP Career Guide – Hitting the Ground Running by Tanya Duncan.

SAP functionality must move through the system landscape, including development and quality systems before reaching production.
On any given project, you can expect to complete configuration and development work in the development client. Development clients are often referred to as ‘D’. ‘D’ refers to the SAP system. Within a system are several clients. Clients are versions of the system that can have differing configuration, development, and data, but are used for a similar purpose.

Once configuration and development is complete in the build phase, this functionality is transported to the quality system. You can expect a different client in the quality system for each type of testing. For example, integration testing and user acceptance testing will likely be in different clients so they can use different data.

Most projects have a ‘Golden Client’ which is the ideal version of configuration and development work. No testing or transactional postings should be made in the golden client. It is available to create a new client copy using the golden client as an example.

During each transition to a new client, a mock cutover is executed to practice the cutover to production at go-live. In a mock cutover, configuration and development is moved, data is converted, interfaces are turned on, and manual steps are executed to prepare the system.

Once functionality is completely tested and business users are satisfied, the project prepares for the real cutover to the production system. There is only one client in the production system.

Since many SAP projects have multiple waves, or releases, of functionality in progress, multiple system ‘rails’ may be used to move to production. Often there is a ‘+1’ rail which is a separate line of development and quality which feeds into the other rail before moving to production. As a project team member, it is important to understand your project’s system landscape and how your functionality will move through to production.