What is the MOST important consideration when selecting key performance indicators (KPIs) for control monitoring?

Stable cost is a practical consideration but less critical than the consistent ability to monitor the control's performance.

Tailoring information by removing outliers can sometimes be necessary for accurate analysis, but the foundational requirement is the consistent availability of the raw data itself.

While KPIs should ideally be quantifiable, consistent availability ensures that whatever can be measured, is measured regularly.

Consistent availability of source information is paramount because control monitoring is an ongoing activity. If data is sporadically available, the KPI cannot be reliably tracked, leading to gaps in understanding control performance and potential unaddressed risks.