Which option describes 'Exceptions' in function modules?

In the context of function modules within SAP, 'Exceptions' indeed serve a specific purpose related to error handling during execution. When a function module encounters a situation where it cannot successfully complete its task—perhaps due to invalid input, a resource issue, or some other unexpected condition—it can signal this failure through exceptions. This allows the calling program to understand that something went wrong and to take appropriate actions, such as logging the error, alerting users, or triggering alternative workflows.

The way exceptions are defined and handled is crucial in ensuring robust application behavior and can prevent cascading failures in larger systems. This mechanism promotes good coding practices by encouraging developers to consider and handle various error scenarios gracefully rather than allowing unhandled errors to disrupt workflow.

The other options touch on aspects related to function modules but do not capture the essential nature of exceptions as indicators of execution problems. For instance, while exceptions need to be declared in the function interface in some cases, their primary role is to indicate errors, not simply to contribute to the interface structure. Similarly, exceptions do not inherently return values, and they are not generally considered optional parameters; rather, they are a fundamental part of error management.