In certain circumstances the Service Level Specifications provide for allowable response and rectification times for Performance Failures or Unavailability Events. A Performance Failure or Unavailability Event occurs when the Contractor fails to respond or rectify within the time allowed or to meet the minimum requirements expected during that time. In a number of circumstances, such as delivery of meals within an agreed time, no response or rectification will be practical so a Performance Failure or Unavailability Event will occur immediately.