So I'm assuming you have 2 date fields? 1 which says when a job was booked to start and another when a job was finished? Along with another field that states what type of job it is? I can give a suggestion based on my assumptions of your data but without details I can't be sure it's going to be anything close to what you need.....
Assumptions
{table.jobtype} = The type of job, ie prescheduled, asap etc..
{table.booktime} = time a prescheduled job was booked to start, or time an emergency or asap job was received?
{table.pickuptime} = time the job was picked up...
Method
Create a formula, for the example we'll call it
{@late}...
datetimevar adjpickup:=
if {table.jobtype} = "ASAP" then dateadd("n",60,{table.booktime}) else
if {table.jobtype} = "Emergency" then dateadd("n",10,{table.booktime})
else {table.booktime};
if {table.pickuptime} > adjpickup
then "Late"
else "On time"
If that's isn't anything close to what you want you need to provide alot more detail about what you're working with.
Thanks,
Ryan.