Thomas Bolton, Ltd., a copper component manufacturer in the United Kingdom, addressed a problem in the production of copper billet components similar to that encountered by Bethlehem Steel. Scrap copper metal is melted, cast into "logs", then cut into varying sizes, or "billets". The objectives of this operation included:
- Selecting feasible cutting patterns, so the waste is less than the minimum billet size required.
- Minimizing the total time required to produce the logs.
- Meeting the schedule of the milling plant.
The variables included:
- Customer demand of cutting patterns for billets.
- Order sizes of billets.
- Scheduled hour of operation.
- Weight of scrap copper melted.
- Molten copper available at the beginning of each day.
A computer program was designed to address this problem over the time frame of a week. Alternate heuristic methods can be considered for an overall optimal solution.