To understand what performance actually is, it is always good to begin with the customer. As shared in the previous chapter, the SDDC is providing a service, not a system. We have seen this in almost all customers. Whether the application team or VM owner pays for the service or not, it is a service. The existence of a chargeback model is practically optional. VM owners no longer own, hence care, about the underlying infrastructure.
Here is a common story often told in the virtualization community, which will resonate with you as an IaaS provider:
A VM owner complains to you that her VM is slow. It was not slow yesterday. Her application architect and lead developer have verified that: