How to track the source of brief spike in number of processes?

Issue

• Every Saturday at 7 PM we are getting around 100 times more processes spike.
• Readings for proc/s in sar report suddenly increase around 7 PM. How to find out what is causing this spike in number of processes?

00:00:01       proc/s
19:00:01         3.08
19:02:23       308.69
19:02:53         7.59