A computer implemented method for optimizing a delivery or settlement process for a plurality of portfolios of a plurality of participants. Data records indicative of obligations between the plurality of participants are identified. A weighted directed graph data structure is generated that comprises vertex data records representing the plurality of participants and edge data records representing the obligations between the participants. All paths of edge data records where a vertex data record is reachable from itself in the weighted directed graph data structure are identified. The data records indicative of obligations between the plurality of participants are altered based on the identified paths.