Calculate Azure SLA
The Service Level Agreement (SLA) for a specific Azure service represents the uptime guarantee for that service. If you combine multiple Azure services in your solution, the overall SLA for your solution will depend on the individual SLAs of each service and how they are used.
But what is the actual SLA if I use multiple services?
That's not so easy and, above all, it's not possible to give a blanket answer. It depends on the overall solution - and how these services work together.
Product Calculation: in product calculation, each SLA is combined so that a product is calculated at the end: 99% * 98% * 97% = 95,03% The problem and the big criticism with this calculation is that services run individually and the real SLA cannot be reflected in the calculated product.
Assumption of the lowest SLA: The SLA of the Solution is calculated based on the service that is used, which has the lowest SLA. The problem with this approach is that not every service is necessarily required for operation. Thus, a deployed platform may have a much higher SLA than the lowest used service.
To calculate the overall SLA for your solution, you will need to consider the individual SLAs of each Azure service and how they are used in your solution. You may also want to consider any additional resilience measures, such as Azure Availability Zones or Azure Availability Sets, to increase the overall availability of your solution.