Rerunnable

Rerunnable is an adjective used to describe a process, program, or operation that produces the same output or achieves the same result each time it is executed with the same inputs and under the same conditions. This consistency is a key characteristic of deterministic systems. For example, a rerunnable calculation will always yield the exact same numerical answer if the input values remain unchanged.

In software development, rerunnability is highly desirable, especially for tasks like data processing, testing, and building. A rerunnable build process ensures that compiling the same source code multiple times will always result in identical executable files. This predictability is crucial for debugging, version control, and ensuring the integrity of software releases.

Non-rerunnable processes can be problematic because their outcomes can vary due to factors like random number generation, external dependencies that change, or time-dependent operations. For instance, a test that relies on the current date and time might not be rerunnable in the same way on different days, potentially leading to false positives or negatives. Identifying and mitigating non-rerunnable aspects of a system is often a goal in achieving robust and reliable computing environments. The concept is closely related to idempotency, where applying an operation multiple times has the same effect as applying it once.