ERP systems are typically built on a three-tier architecture, which provides scalability, flexibility, and maintainability. This structure divides the system into three layers: the Database layer, the Application layer, and the User Interface layer. Let’s delve deeper into each of these layers:
1. Database Layer (Data Tier):
- Function: This is the foundational layer where all the data related to the ERP system is stored. It contains the databases and ensures data integrity, consistency, and security.
- Relational Databases: Most ERP systems use relational databases (e.g., Oracle, Microsoft SQL Server, MySQL) to store, retrieve, and manage data efficiently.
- Database Servers: Physical or virtual servers that host the database system and handle database operations.
- Storing transactional data.
- Maintaining data relationships.
- Ensuring data backup and recovery.
- Providing concurrency controls and data security.
2. Application Layer (Logic Tier):
- Function: This layer contains the business logic, processes the data, and controls the application’s functionality. It acts as a mediator between the user interface and the database.
- Application Servers: These servers host the ERP application and business logic. They process client requests and perform operations on the data.
- Business Logic: Set of rules, workflows, and algorithms that the ERP system follows to process data and execute tasks.
- Handling business processes like calculations, data processing, and rules enforcement.
- Ensuring integration with other systems or modules.
- Managing transactions and ensuring data consistency.
- Scalability and load balancing.
3. User Interface Layer (Presentation Tier):
- Function: This is the layer with which end-users directly interact. It provides a visual interface to access the ERP system’s features and data.
- Client Software: Could be web browsers (for web-based ERPs) or specific client software installed on user devices.
- Graphical User Interface (GUI): Provides a user-friendly environment where users can input data, execute tasks, or retrieve information.
- Displaying data to users in a comprehensible format.
- Capturing user inputs and requests.
- Ensuring a responsive and interactive user experience.
- Providing navigation, help features, and customization options.
In summary, the three-tier architecture of ERP systems is designed to separate the concerns of data management, business logic processing, and user interaction. This separation provides several benefits: it ensures the system is scalable (each tier can be scaled independently), maintainable (changes in one tier don’t necessarily affect the others), and flexible (different tiers can be hosted on different machines or even in different locations). This architecture plays a crucial role in the efficiency and robustness of ERP systems.