Network Aggregation Concepts,

This report considers the use of aggregation in modeling and solving network based logistics planning problems. Aggregation combines, or pools, certain attributes of a problem to facilitate its modeling and solution. Frequently, after the model is solved it is necessary to disaggregate the pooled attributed to their original level of detail. This allows determination of the acceptability of the model output in making the suggested decisions. If the aggregate model yields an unacceptable solution, a mechanism is required by which solutions can be modified to make it acceptable. Aggregation imposes a natural decision hierarchy with higher level aggregate decisions restricting lower level, more detailed, decisions. For large scale planning situations requiring involvement of a number of participants with skills in different areas, this can be very important.