Issue with parallel flows when activity Chaining is applied

Question

Hello All, 
 I have a scenario where I am calling the process from web API, to get this completed faster I have added few flows in parallel using AND gateway and these paths has to complete to return the response from web API hence I have applied activity chaining on both the flows. 
 With this implementation I have observed that, even we are having parallel flows using AND, because activity chaining, only one path is executing first and then other is starting which delaying time of execution. 
 Why chaining is over-passing AND functionality here? Any thoughts on this? 
 Please find below example process.

Thanks! 
 Priyanka

Mike Schmitt · Answer

Logically, chaining can only really apply across one branch of an AND gateway.

Mike Schmitt · Answer

I'm unclear what parallel flows buys you here when both flows are unattended. You may as well put all the items in sequence (especially since when the two flows are running in parallel, even if chaining worked there'd be no way to assure what order the nodes execute in, meaning you should be able to make the two paths sequential anyway).

David Jimenez · Answer

No , it means that you won't be able to predict what it will happen. 
 
 And yes , you must avoid the use of an AND gateway in this case, try to implement it in a sequential flow

Harsha Sharma · Answer

As others suggested here, its better to merge both parallel flows so they execute sequentially. Also try to keep the chaining till the node on which the parent process depends or expects output from, because activity chained nodes themselves can slow the performance/execution of process.

Priyanka! · Answer

Thank you all for replying to this thread, as mentioned by Mike Schmitt and David Jimenez chaining need deterministic path to execute on priority. My issue got resolve applying chaining for one path and removing from other. This way chaining is not breaking anywhere and parallel execution is also happening as expected.