End User

Enhanced Definition

In the mainframe context, an **End User** is the individual who directly interacts with business applications running on z/OS, typically without needing knowledge of the underlying operating system, programming languages (like COBOL), or system utilities. They consume the services provided by mainframe applications to perform their job functions or access information. An End User, in the mainframe context, is the individual who directly interacts with business applications running on the z/OS system to perform their job functions, without needing knowledge of the underlying operating system, programming languages, or infrastructure. They are the final consumers of the services and data provided by mainframe applications.

Key Characteristics

- Application-centric Interaction: End users interact primarily with the application's interface (e.g., 3270 green screen, web front-end, mobile app) rather than directly with z/OS commands or utilities.
- Business Function Focus: Their interaction is driven by specific business processes, such as processing transactions, querying data, or generating reports critical to the organization.
- Limited System Access: They typically have highly restricted access to system resources, limited to what the application provides and their security profile dictates via security products like RACF or ACF2.
- Diverse Interface Types: While historically interacting via 3270 terminals, modern end users may access mainframe applications through web browsers, mobile apps, or other graphical user interfaces that front-end the mainframe.
- Data Consumers/Producers: They are often responsible for inputting new data into mainframe databases (like DB2 or IMS DB) or retrieving existing data for decision-making.

Use Cases

- Bank Teller: Using a CICS-based application on a 3270 terminal to process customer transactions, check account balances, or open new accounts.
- Insurance Agent: Accessing an IMS DB/DC (Database/Data Communications) application to retrieve policy details, process claims, or update customer information.
- Airline Reservation Agent: Interacting with a high-volume transaction processing system (often CICS or a custom TP monitor) to book flights, manage reservations, and check availability.
- Customer Service Representative: Utilizing a web-based portal that interfaces with backend mainframe systems to resolve customer inquiries or provide support.
- Online Banking Customer: Interacting with a mobile or web application whose backend processes customer requests (e.g., balance inquiries, transfers) on a z/OS system.

Related Concepts

End users are the ultimate beneficiaries of the entire mainframe ecosystem. Their interactions drive the execution of COBOL or PL/I programs, which are managed by CICS or IMS TM transaction managers. These programs then access data stored in DB2, IMS DB, or VSAM datasets. JCL is used by developers and system administrators to build and deploy the applications that end users consume, but end users themselves do not directly interact with JCL. System programmers and operations staff ensure the z/OS environment is stable and performant to support the end user's workload.

Best Practices:

User-Centric Design: Even for 3270 applications, design screens and workflows to be intuitive, efficient, and minimize keystrokes for common tasks, considering the end user's perspective and job role.
Performance Optimization: Ensure applications respond quickly, as slow response times directly impact end user productivity and satisfaction. This involves optimizing COBOL code, database queries, and network latency.
Robust Error Handling: Provide clear, actionable error messages to end users, guiding them on how to resolve issues or whom to contact for support, rather than cryptic system codes.
Comprehensive Training and Documentation: Equip end users with the necessary knowledge and resources to effectively use mainframe applications, whether through formal training or accessible documentation.
Security and Authorization: Implement granular security controls (e.g., using RACF or ACF2) to ensure end users only have access to the data and functions necessary for their role, protecting sensitive information.