From my experience there is not necessarily a risk/benefit ratio, but rather the company performs an analysis where they weigh all the risks and compare them to the benefits and make a decision whether or not to proceed with the project. Often they get a clinician’s input when making this determination as well. However, an output of this analysis could be that the risks are too high, which means either the project will be stopped or will not resume until there is a plan in place that will reduce the risk to an acceptable level.