Thanhs for your reply , would you tell me the name of the parameters ?
Can we find it in Host & Service Paramaters as well ? and can we apply to all services ( we have many custom services that we 've developed for our custom needs )
As far as I know, these features (trend computation and levels per time range) are only available in certain checks that have explicitely been written to support these. Most notably, you can use trends in various disk and temperature checks.