# Calling Other Processes ## Overview In Kognitos, one process can call and run another process. The called process is referred to as a **subprocess**. There are many advantages of using subprocesses: * **Modularity:** Decomposing automations into smaller processes enhances structure and organization. * **Readability:** Well-organized automations are easier to read and understand. * **Scalability:** Automations can be scaled to handle multiple tasks. * **Maintainability:** Isolated processes simplify debugging and updating individual components. ## Mechanisms There are several ways to call another process in Kognitos: 1. [**Run a Subprocess**](https://docs.kognitos.com/legacy/legacy-experience/writing-automations/calling-other-processes/run-a-subprocess): This method is ideal for single-run scenarios where you need to capture the result and status of a subprocess. 2. [**Invoke a Subprocess**](https://docs.kognitos.com/legacy/legacy-experience/writing-automations/calling-other-processes/invoke-a-subprocess): This method is useful for scenarios where the parent process can continue executing without waiting for the subprocess's status or completion. 3. [**Start Parallel Runs**](https://docs.kognitos.com/legacy/legacy-experience/writing-automations/calling-other-processes/start-parallel-runs): This method provides control over parallel execution when handling multiple subprocesses simultaneously. ### Comparison
AspectRunning a SubprocessInvoking a SubprocessStarting Parallel Runs
Syntax
run <procedure name>

invoke <procedure name>

start a run where
    the procedure is <procedure name>
Execution StyleSequential ProcessingSequential ProcessingParallel Processing
PerformanceSlower overall (each subprocess runs separately)Slower overall (each subprocess runs separately)Faster for many items (since runs happen in parallel)
General UsageWhen tasks or items are independent and you want the result / status of a runWhen tasks or items are independent and you don't need the result / status or a runWhen tasks or items are dependent or rely on one another
Document ProcessingUse when each document is independent and can be processed in isolationUse when each document is independent and can be processed in isolation



Use when documents are dependent on one another, or the final outputs need to be aggregated


Example
run "to process the sales order"
    the attachment

invoke "to process the sales order" with
    the file is the document

get the attachments
process each attachment as follows
  start a run where
    the procedure is "to process the sales order"
    the attachment
wait for the runs
get the runs's results as the sales orders
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