when we are performing stock picking validation, the system takes time to render the view. 

We have already checked in log file to check if the problem came from the backend but everything was ok, it's safe to say that the treatment of each step in the function has done successfully. And there is no sign of block. However, the page loads for a long time before rendering the view. 

What might be the reasons of that ?

What should we do ?

Any help is welcome.

Thanks