Advantages

• Automatic.

• Impact on response time is quantifiable.

  • Performance be adapted to the user’s preference.

• Works well in the presence of multiprogramming.

• Irregular processor utilization is not a problem.

• Implementation requires very little state.

  • Weighted average: two counters.
    • Rescale to adapt to temporal variations.

• Existing interval-based schemes:

• No feedback about service quality.

• Only work well if processor utilization is regular.