What are the common time-domain specifications for control systems?

Time-domain specifications describe transient response to step input: rise time (time to go from 10% to 90% of final value), peak time (time to first peak), overshoot (percentage exceeding final value), settling time (time to stay within 2% or 5% of final value), and steady-state error. These specifications are used to evaluate system performance and guide controller design. Trade-offs exist - reducing rise time often increases overshoot. Design targets depend on application requirements.