Techniques for processing I/O operations in a data storage system may include: receiving I/O operations directed to a logical device associated with a service level specifying a target I/O response time goal; receiving a input identifying whether to calculate an observed I/O response time for the logical device using only an internal processing time associated with processing performed within the data storage system when servicing I/O operations directed to the logical device; determining, in accordance with the input and the I/O operations directed to the logical device, the observed I/O response time for the logical device; determining a service level violation for the first logical device whereby the observed I/O response time violates the service level; and responsive to determining the service level violation whereby the observed I/O response time violates the service level, performing processing to alleviate or remove the first service level violation.