What does this equation mean?

The arithmetic is simple once both prices are in hand, and generalizes across any reserved-capacity product structured this way. Let $P_r$ be the reserved capacity’s price per hour, $Q_{\max}$ the maximum throughput it sustains per hour at full utilization, and $c_{\mathrm{od}}$ the effective on-demand cost of the equivalent work. At actual utilization u , the effective cost per unit under reservation is $P_r$ / (u \, $Q_{\max}$) , and reservation wins exactly when $u^{*} = \frac{P_r}{Q_{\max}\, c_{\mathrm{od}}}$. is cleared. Utilization above $u^*$ favours reservation; below it favours paying as you go. The formula’s value is what it forces a team to measure honestly before signing: not peak throughput or a favourable week’s average, but utilization sustained across the full commitment term including the slow periods — capacity sized to a launch-week peak and left running at a quarter of that traffic for the following eleven months has pre-paid idle time at the reserved rate.