Availability is one of the protection objectives in cybersecurity. When deploying new systems, the design must cater for spare capacity. Usage patterns need to be understood too as this will surge capacity demand instantaneously.
Capacity refers to bandwidth, storage, processing speed. This must be estimated in the next 3-5 years with the projected growth rate plus the peak demand, setting threshold to trigger alert to resolve the capacity issue. It can be adding more storage, or archiving historical records offline, or deleting records per corporate retention policy.
It is part of system management to maintain a healthy cyber environment to run business. Otherwise, business services will be interrupted.