How to use HSF and Custom Fields to get the response time between multiple screens/components of a CICS transaction. HSF provides the start time for a CICS transaction and with the help of two available functions (ES_Write_Custom_HSF or ESCSTHSF ) that can be called from a application program, the start time and end time for each different screen/component can be written using HSF Custom Fields to the HSF file for later review.

Full article: https://portal.microfocus.com/s/article/KM000016363