“Budget variance (%)” is a valid KPI when defined clearly (actual vs budget, period, scope). At an organizational level, the tolerance band is typically tight , because large deviations indicate poor forecasting, weak cost control, or major operational surprises. Among the options, +/− 3% is the most reasonable limit that reflects disciplined financial management while allowing for normal variability. +/− 50% or +/− 97% would be so wide that the KPI loses practical meaning—almost any performance would appear acceptable, undermining accountability. The key selection principle here is relevance and actionability : thresholds should differentiate normal variation from conditions that require management intervention. In context, tolerance bands may differ by industry volatility (e.g., commodity-driven businesses may accept wider bands) and by what is being measured (opex may be tighter than capex). Implementation should also clarify whether variance is favorable/unfavorable depending on cost vs revenue budgets and how timing differences are treated. Proper documentation avoids gaming through reforecasting or shifting accruals.