aggMultResultNodes.add(new ResultNode(plan.getTree().getRoot(), new WeightedMultiplication(), plan
.getAlternativesDefinition().getConsideredAlternatives()));
aggSumResultNodes.clear();
// calculate result nodes for all considered alternatives
ResultNode sumResultNode = new ResultNode(plan.getTree().getRoot(), new WeightedSum(), plan
.getAlternativesDefinition().getConsideredAlternatives());
aggSumResultNodes.add(sumResultNode);
knockedoutAlternativePresent = acceptableAlternatives.size() != plan.getAlternativesDefinition()
.getConsideredAlternatives().size();