When performing a capacity planning exercise, when would taking measurements be most approriate?

For effective capacity planning, measurements should be taken during periods of successful, normal operation, including peak load times, to accurately establish a baseline of resource utilization under typical and expected workloads.

Taking measurements during an overload or an episode captures abnormal system behavior and skewed resource usage, which is not representative of normal operating conditions for proactive capacity planning.

Measuring after an overload or an episode only provides insights into the system's state post-problem, which is reactive and less useful for proactive capacity planning and forecasting future needs.

While replacing hardware is part of capacity management, taking measurements only after replacement doesn't provide the historical baseline or trend data necessary for comprehensive capacity planning; continuous or periodic measurements are generally required.