Delay Type

Reason

Repeated calling of DATE/TIME services

A program or one of its subroutines repeatedly calls the date/time operating system services.

Reduce this type of delay by obtaining the date once and use it for the entire program execution.

Excessive storage management activity

A program or one of its subroutines is allocating and freeing areas of virtual memory excessively.

Storage management is an expensive function that causes application delays if not properly utilized.

You can reduce delays resulting from excessive storage management by designing the program to allocate and free storage less frequently.

Excessive use of timer services

A program or one of its subroutines uses the timers provided by z/OS or an application enabler such as CICS, to control a time-dependent feature of the application.

Timer services should be used sparingly since their use can cause system delays.

Extensive security calls

A security system protects all physical and logical system resources, and calls to the protection routines are causing excessive CPU use.

Excessive security implementation in an online environment can account for up to 10 percent of processor usage.