A refined cost-based approach to assembly scheduling

Increased emphasis on control of work-in-process costs in assembly scheduling of large, complex items leads to increased needs for aids to foremen in dealing with schedule changes. The task is complicated by constraints on resources that often require that activities are begun earlier than a just-in-time schedule would otherwise dictate. A criterion used in prototype tandem knowledge-based decision-aiding systems in the past was based on the assumption that investment costs do not compound. This can provide misleading choices in some cases. The present work refines the criterion previously used by including the compounding costs of holding subassemblies in inventory. A simplified version of the new formula is developed which provides simple rules for deciding which activities to start early if necessary. Numerical comparisons are made between the criteria.