Which component is responsible for executing and running process instances in Appian architecture?

The component responsible for executing and running process instances in Appian architecture is the Process Execution Engine. This engine is a core part of Appian's workflow framework, managing the lifecycle of process instances, including their initiation, execution, and termination.

The Process Execution Engine not only interprets the process model but also manages various tasks involved in executing the process flow, such as assigning tasks to users, managing timers, and tracking state. This is critical for ensuring that business processes are automated and executed as designed, contributing to efficiency and accuracy in process workflows.

Other components, while important in the overall architecture, serve different purposes. Process Model Definitions define the structure and flow of a process but do not execute them. The Process Analytics Engine focuses on collecting and analyzing data related to process performance, providing insights rather than executing the processes themselves. The Appian File System is used for storing files but does not play a direct role in the execution of process instances. Thus, the Process Execution Engine clearly stands out as the sole component dedicated to this essential function within Appian's architecture.