Using Feasibility Cuts to Accelerate the Convergence of Modes
Abstract
System for Closure Optimization Planning and Evaluation (SCOPE) is a system for closure planning developed by the Production and Distribution Research Center (PDRC) at Georgia Tech. Two types of decisions are involved in closure planning: 1) allocate the available capacity of different asset types to transportation channel, and 2) load and schedule the various movement requirements to these channels in accordance with the allocated capacities. The specific linear program associated with MRMATE is of the special type known as the minimal cost generalized network flow problem. Its special structure allows fast solution even for very large problems. However, the channel configuration created by LIFTCAP is not guaranteed to allow delivery of all the movement requirements until the final iteration. In many cases finding a feasible solution, i.e. channel configuration which allows 100% delivery, when one exists, is as hard as finding the optimal solution. The network of MRMATE is examined and special classes of cutsets (partitions of the node set of the network) is identified in this network which are themselves associated with necessary conditions for the network to admit feasible flow. Some of these conditions are then added to LIFTCAP as additional constraints in order to make the channel configuration produced by this sub) problem closer to feasibility. These cuts are thus termed 'feasibility' cuts.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1988
- Accession Number
- ADA198715
Entities
People
- H. D. Ratliff
- John J. Jarvis
- Moshe Eben-chaime
Organizations
- Georgia Tech