In a recent paper, Christy and Kanet (1990) examined the performance of several dispatching rules in a forbidden early shipment environment. Their primary performance measure was time-weighted inventory value. This study re-examines their results using a new model, with a net present value (NPV) performance measure. The results show that using NPV and inventory objectives lead to different scheduling decisions. Also examined are the reasons for relatively poor performance of operation-based due date rules.