rdisp/max_dynamic_wp_alive_time is a SAP Parameter attribute which is used to control Maximal alive time of a temporary dynamic workprocess information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
If all processes of a type (for example, DIA) of a server are in state
'Stop' and dynamic work processes have been configured, the Dispatcher
starts work processes to resolve any possible blackages. These processes
can then be used for a specific time. The parameter defines the time
period from which dynamic processes that are no longer are then ended
See SAP Parameter Documentation for full SAP documentation for this profile parameter.