# 5-A.1 Update System Landscape ## Purpose The System Landscape Diagram * describes * the IT architecture of your organization (or a department of that) * the services provided by the organization * the systems required to provide those services * gives an overview of what systems exist in an organization and how they interact with each other * informs about * dependencies & bottlenecks * reuse within the organization * usage / adoption of building blocks (for example a central Identity component) * redundancies & duplication ## Scope A single diagram can usually only hold the information on a subset of systems. In the context of this playbook, the System Landscape should describe * a single organization * all software systems of that organization that * are necessary to provide the e-government services of that organization * follow the same or similar governance (for example all systems using GovStack) * all interfaces between those systems * all outside interfaces of those systems * should be grouped into clusters representing the services provided by the organization (one cluster - one service / Fachverfahren) ## How to do it * If the System Landscape Diagram already exists, just update it, by adding the information from the System Context diagram. * If it does not exist, it can easily be created from System Context * It might be useful to add additional boxes to create groups of systems, where suitable * Optionally: if you want to further complete the System Landscape, go back to the previous step and create System Context for further systems. This way you will document the Government Architecture step-by-step. Example System Landscape Diagram:

Adapted from https://c4model.com (CC BY 4.0). Changes made.