2.1 Overview: The High-Level System Landscape

Understanding the technical architecture of SAP Fiori is essential for a successful implementation. It is not a monolithic system but rather a decoupled, multi-component landscape designed for security, scalability, and flexibility. This architectural choice has profound consequences, as it separates the user interface layer (front-end) from the business logic (back-end), allowing for independent maintenance and upgrades. The key players in this landscape include a web dispatcher to handle incoming requests, a dedicated front-end server for UI components, a back-end server containing the business data, and, for advanced applications, the SAP HANA database.

2.2 Deep Dive: Core Architectural Components

The SAP Fiori architecture is composed of four primary components, each with a distinct and critical role.

1. SAP Web Dispatcher (Reverse Proxy) The SAP Web Dispatcher serves as the initial entry point and gatekeeper for all HTTP and HTTPS requests from end-users. Its primary function is to act as a reverse proxy, inspecting incoming traffic and determining whether to accept or reject the connection based on security rules. Once a request is accepted, the Web Dispatcher is responsible for routing it to the correct application server, ensuring that user traffic is managed securely and efficiently before it ever reaches the core application servers.
2. SAP ABAP Front-End Server This server contains all the user interface (UI) components of the Fiori system. It is responsible for rendering the user-facing elements and is intentionally separated from the core business logic. Its key contents include:
   • Central UI Add-On: This includes the SAP UI5 control library, which provides the building blocks for Fiori apps, and the SAP Fiori Launchpad, the central entry point for users.
   • Product-Specific UI Add-Ons: These contain the specific UI code for applications related to different business suites, such as ERP or SCM.
   • SAP NetWeaver Gateway: This crucial component is responsible for establishing the connection to the back-end system. It uses OData services to expose business data and functions to the front-end applications in a standardized way.
3. SAP ABAP Back-End Server The back-end server is the heart of the business operations. It contains the core business logic and the underlying application data. For certain Fiori app types, such as Fact Sheets, it also hosts the Enterprise Search models required to retrieve information. By housing the business logic here, the system ensures that the front-end presentation layer remains distinct from the core processing and data storage.
4. SAP HANA database and HANA XS Engine While not required for all Fiori apps, the SAP HANA database is mandatory for Analytical Apps and Fact Sheets. Specifically, the HANA XS Engine is used to run all Analytical Apps. It contains the Fiori app content and the virtual data models (VDMs) provided through SAP HANA Live. The XS Engine consists of two main components:
   • HANA Live App content: Provides pre-built views and models for the business suite.
   • Smart Business component with KPI Modeler: Enables the creation and monitoring of Key Performance Indicators (KPIs).

2.3 Architectural Variations Based on Application Type

The Fiori system architecture is utilized differently depending on the type of application being run, which has significant implications for infrastructure requirements. While Transactional apps are flexible and can run on any database, Fact Sheets and Analytical apps impose a strict requirement for the SAP HANA database.

• Fact Sheets rely on powerful search capabilities to function. The search models they use pull data directly from the SAP HANA database to provide users with drill-down access to key business objects.
• Analytical apps source their data directly from the HANA XS Engine. They leverage Virtual Data Models (VDMs) within HANA Live to perform complex aggregations and calculations on large volumes of data in real-time.

Communication between the SAP ABAP Front-End and Back-End servers is securely handled using a Trusted RFC (Remote Function Call) connection, which allows for seamless and authenticated data exchange between the two systems.

2.4 System Requirements: Hardware and Software

Implementing a SAP Fiori landscape requires adherence to specific hardware and software prerequisites.

Minimum Hardware Requirements

The following table summarizes the minimum hardware specifications for the SAP NetWeaver Gateway front-end server:

Software Dependencies

The software components needed on the front-end server depend on the version of SAP NetWeaver being used:

• For NetWeaver 7.31, the central UI Add-Ons and SAP NetWeaver Gateway components must be installed separately.
• For NetWeaver 7.4, these components are included as part of the standard installation, simplifying the setup process.

For Analytical and Fact Sheet applications, SAP HANA Live for SAP ERP is a required component. It is delivered as a separate package to be installed as an add-on for SAP HANA. Its product details are:

• Release: 1.0 SPS10
• Software Components: HCO_HBA_ECC
• Dependency: SAP HANA Appliance Software SPS 08 or higher

This module has outlined the fundamental architecture of SAP Fiori. The next module will provide a deeper examination of the key application types that this architecture is designed to support.