Process Activity Breaking

Question

Hi Everyone 
 I have one subprocess process model which is having 10 nodes which includes 2 xor gateways ,4 sync record smart service and 4 query database smart service. Complete process is activity chained in parent process we have one ui on click of button this subprocess will execute its should come back to same ui for that we have activity chained complete parent and child process. Now the issue is when we have 3 query database and 3 sync record smart service all works good .We got new requirement to sync one more record that time we have added one more sync smart service that time the process is not working as before.Later in subprocess which is have all sync smart service we just removed 2 xor gateways to decrease the nodes that time its worked properly.What would be the reason for that? 
 Thanks in advance for the people who helps me to understand this .

Shubham Aware · Answer

AFAIK, Multiple activity-chained sync record smart services cause record locking conflicts and execution delays. Removing XOR gateways reduced complexity and execution time, preventing lock conflict and allowing the process to complete successfully.

Mike Schmitt · Answer

You could probably increase the "chained efficiency" and thus decrease the user waiting by doing something more efficient with your multiple Sync Record smart services. And why are you using "Query Database" at all? I recommend against ever using that unless there's a critical need for something *only* it can do, which is very rare in my experience. 
 The Sync Record smart services, if they aren't **directly** needed for the next user-facing task, could be run in an asynchronous-style side process flow that will run simultaneously to the user's new task. This of course somewhat depends on what you're doing/showing/querying on your next user task, which you have not specified. 
 Can you post a screenshot of your process flow so far, or at least a general outline of it?