BTS - Business Transaction Services

Enhanced Definition

BTS (Business Transaction Services) is a CICS facility that enables the definition, execution, and monitoring of long-running, multi-step business processes within the CICS environment. It allows a series of CICS transactions or programs to be linked together to form a coherent business process, providing persistence and recovery capabilities across multiple user interactions or system events.

Key Characteristics

- CICS-native workflow: Fully integrated within the CICS transaction processing environment, leveraging core CICS services for transaction management, security, and resource access.
- Process-oriented: Organizes work into processes, which are defined sequences of activities (CICS transactions or programs) that can span multiple CICS transactions and user sessions.
- Persistent state: Maintains the state of a business process in a dedicated BTS repository (typically a VSAM KSDS or RLS file), allowing processes to be suspended and resumed.
- Asynchronous execution: Supports asynchronous execution of activities, enabling complex workflows where steps might be triggered by events, time delays, or explicit program calls.
- Recovery and restart: Provides robust recovery mechanisms, ensuring that processes can be restarted from a known point after a system failure, maintaining data integrity.
- Event-driven: Activities within a process can be triggered by internal CICS events, external events, or explicit program calls from application programs.

Use Cases

- Order fulfillment: Managing the lifecycle of an order from submission through inventory check, payment processing, shipping, and notification, potentially involving multiple CICS transactions and departments over time.
- Claims processing: Orchestrating the steps involved in processing an insurance claim, including data entry, validation, approval workflows, and payment disbursement, where each step might be handled by different users or systems.
- Customer onboarding: Guiding a new customer through a series of data collection and setup steps that might require multiple CICS screens and backend updates over several interactions or days.
- Complex data entry workflows: Implementing multi-screen data entry applications where user input needs to be collected over several interactions, with the process state preserved between screens and sessions.

Related Concepts

BTS extends the capabilities of traditional CICS transactions by allowing them to be chained together into long-running, stateful processes, whereas standard CICS transactions are typically short-lived and stateless. It provides a workflow engine *within* CICS, complementing external workflow or BPM systems by handling the CICS-specific parts of a larger enterprise process. BTS leverages core CICS services for transaction management, security (e.g., RACF), and resource access to databases like DB2, VSAM, or IMS DB.

Best Practices:

Careful process design: Thoroughly model the business process using tools like CICS Explorer to define activities, transitions, and comprehensive exception paths before implementation.
Efficient repository management: Regularly monitor and manage the BTS repository file to ensure optimal performance and prevent growth issues. Consider using RLS (Record-Level Sharing) for the repository for improved availability and concurrency.
Robust error handling: Design processes with comprehensive error handling and recovery logic for each activity to ensure graceful degradation and restartability, logging failures appropriately.
Security integration: Implement CICS security (e.g., RACF) to control access to BTS processes and activities, ensuring only authorized users or applications can initiate or advance processes.
Performance tuning: Optimize the CICS programs involved in BTS activities for performance, as inefficient programs can impact the overall throughput and responsiveness of long-running processes.