Difference in coverage times based on severity

Hi,

I would like your advice for the following business scenarios we have:

1. SR is covered with contract with covered template.

2. The responded time (Reaction time), should be different based on the severities.

for example:

·         Critical / High – should have 2 hours regardless the SR creation time (even if the SR opened out of business hours and days) – view second example below

·         Medium / Low – should  have 2 hours within business hours/days.

I’m aware of the ‘Work Through’ check box, which I thought may be apply to this scenarios, however I found out that if the SR creation time is out of the defined business hours it not supported the above.