# How to Calculate SLA for a Product

When we work against multiple Azure Services for a Single Product we need to handle the SLA (Service Level Agreement) carefully. It is not min or max or the average of SLA per services. Let's take an example,

Table 1

 Service SLA App Service 99.95% Azure Active Directory 99.9%

What these % means,

 % Downtime/week Downtime/month Downtime/year 90% 16.8 hours 72 hours 36.5 days 99% 1.68 hours 7.2 hours 3.65 days 99.9% 10.1 minutes 43.2 minutes 8.76 hours 99.99% 1.01 minutes 4.32 minutes 52.56 minutes 99.999% 6.05 seconds 25.9 seconds 5.26 minutes 99.9999% 0.605 seconds 2.59 seconds 31.5 seconds

All the SLA of Azure is defines at https://azure.microsoft.com/en-us/support/legal/sla/

Based on Table 1 if an application uses both the Azure Services then the composite SLA of the Application would be

0.9995 x 0.999 = 0.9985005

Hence 99.85%. So it is neither 99.95% nor 99.9% it is altogether different.

Also one need to consider if there is anything in Application which defines its SLA.

Namoskar!!!