What do Process Model Activities represent that can be reused in various processes?

Sub-Processes are a way to encapsulate a series of activities within a process model that can be reused in multiple contexts. When a sub-process is created, it allows for modularization of process logic, meaning you can define a particular sequence of steps in one place and reference it from various parent processes whenever that sequence is needed. This not only streamlines the process design, making it easier to manage and update, but it also promotes consistency across the application by ensuring that the same logic is applied uniformly wherever the sub-process is employed.

Utilizing sub-processes can improve efficiency and reduce the likelihood of errors since any changes made to the sub-process are automatically reflected across all processes that use it. This concept of reusability is critical in process modeling, as it enables developers to build complex workflows without having to recreate commonly used tasks, thus enhancing both productivity and maintainability.

The other options, while important in the context of process modeling, do not encapsulate reusable series of activities in the same comprehensive way as sub-processes do. Task nodes represent individual tasks and are generally specific to the process, event subprocesses are specialized within the context of an event occurring, and process properties define characteristics of the entire process but are not directly reusable activities