Process Model

Question

How do you decide between using subprocesses and keeping everything in a single process model?

varuntejagurrapu · Answer

Hi diyar185976 , 
 Subprocesses are used to modularize reusable or independent logic, improve maintainability, and control execution behavior, while single process models are preferred for simple, tightly coupled flows where separation adds unnecessary complexity. Let's break your question in to few points, just to understand quickly: 1. Reusability (biggest factor) - Breaks individual short processes, which can be reused, ( E.g : Email Reminder with custom templates used in different stages ) 
 2. Separation of concerns ( Keeps logic isolated and maintainable ) - E.g Main process = onboarding, Subprocess = background verification 
 3. Complexity control - E.g - Single process with 40 nodes &rarr; unreadable, where 5 PMs with few nodes 
 4. Independent execution (critical) - use Synchronous - back to back tasks, - Asynchronous, user creation even if related PM fails 
 5. Performance & execution behavior - Subprocess (synchronous) -> parent waits , Subprocess (asynchronous) -> runs independently. 
 Most developers: 
 1. Either dump everything in one process. 
 2. Or overuse subprocess everywhere. 
 Both are wrong, always go with modular design ensuring all the above mentioned points. FYI - Please check documentation to know more about Subprocess - docs.appian.com/.../Sub-Process_Activity.html

Mike Schmitt · Answer

Much of what Varun already wrote above is pretty on-point. I would offer my simpler take: it's not "either-or", and there is no "strictly right answer". Often what happens is a process evolves over time and you realize that certain sections represent functionality you'd rather have reusable across different processes (without having to rebuild it over and over again, and without the risk that it drifts apart in functionality), so you encapsulate those pieces into a subprocess. I do wish the process of accomplishing this were a little bit faster or more painless, but I don't know what's feasible.

Mathieu Drouin · Answer

Mike/Varun have some excellent points. Here is an additional resource with some information you might find useful: 
 community.appian.com/.../how-to-create-memory-efficient-models