How do you calculate the composite between one Service Level Agreement at 99.99% to the 2nd Service Level Agreement at 99.95%.
Thanks for your query, JHM – and Dan is absolutely right – the reason you multiple that is because the probability of an individual service failing is independent of another service failing. So you multiply the SLAs. The composite SLA is lower than individual service SLAs for the simple reasons that there are more points of failure when you add more services.
The multiplication is the same: 99.95 x 99.99 = 99.94.