Which measurement reflects the percentage of sustained bid protests?

The percentage of sustained bid protests is best reflected by the ratio of bid protests to solicitations issued. This measurement directly assesses the frequency at which bid protests occur in relation to the total number of solicitations that have been issued. By calculating this ratio, one can determine how often bid protests result in a favorable outcome for the protestors compared to how many solicitation processes are initiated.

A high ratio indicates a significant number of bid protests relative to the number of solicitations, which can highlight potential issues in the bidding process, such as unclear specifications or perceived unfairness. This ratio is crucial for assessing the effectiveness and integrity of procurement practices, as it shows how often the challenges presented by bidders are recognized and upheld.

In contrast, the other options do not focus on the outcome of the protests or their frequency in relation to solicitations. The number of total bidders, average contract value, and time taken to resolve disputes may provide useful insights in different contexts, but they do not directly measure the percentage of sustained bid protests, thus making the first option the clear choice for this question.