A transation processing monitor is critical in multi-tier architectures. With processes running on different platforms, a given transaction may be forwarded to any one of several servers. Generally, the TP monitor handles all load balancing. After completing each transaction, the TPM can process another transaction without being influenced by the prior transaction. In other words the TPM model essentially is stateless

In general, a TPM provides the following functionality:

• Coordinating resources
• Balancing loads
• Creating new processes as/when needed
• Providing secure access to services
• Routing services
• Wrapping data messages into messages
• Unwrapping messages into data packets/structures
• Monitoring operations/transactions
• Managing queues
• Handling errors through such actions as process restarting
• Hiding interprocess communications details from programmers