Actiondepend

Actiondepend is a concept used in workflow design and automation to denote that the execution of a given action is conditioned on the completion of one or more prerequisite actions or the satisfaction of certain conditions. The term combines action and dependence and is commonly applied in planning, orchestration, and automation contexts. In practice, an actiondepend specification describes a dependency relation within a directed graph of tasks, where edges indicate that the target action should wait for its predecessors before starting.

In implementation, actiondepend is expressed as dependencies in workflow engines: tasks declare upstream tasks, and the engine schedules tasks once their dependencies are resolved. This approach allows parallelism by enabling actions with independent predecessors to run concurrently. Actiondepend can be extended with conditional or dynamic dependencies, where a dependency is determined at runtime based on data or outcomes of earlier actions.

Examples include a data processing pipeline where load_data must complete before transform_data, or a deployment pipeline where run_tests depends on build_artifact. Another case is a rollback action that depends on a failure signal from monitors.

Relation to related concepts includes dependency graphs, task ordering, and gating in automation systems. Unlike rigid sequences, actiondepend emphasizes explicit dependency constraints that guide execution order without prescribing exact timing.

Limitations involve cycles in dependencies that render execution infeasible, and the need for strategies to handle partial failures, such as retries or fallback actions. See also: workflow orchestration, DAG scheduling, and dependency graph concepts.