Scheduling rule selection for the forbidden early shipment environment: a comparison of economic objectives

Abstract

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 resultsshowthat usingNPV and inventoryobjectives lead to different scheduling decisions. Alsoexamined are the reasonsfor relatively poor performance of operation-based due date rules.

An Experimental Comparison of Time‐Based and Economic‐Based Scheduling Methods to Maximize Net Present Value*

“…This function is similar to that used in [19] [21] [22] and is similar in basic form to the function in [12] for a multi-machine NPV application. Key differences in (3) and the functions used in previous studies are in the cash flow timing and specific form of tardiness costs.…”

A comparison of job shop dispatching rules using a total cost criterion

“…Using a job net present value criterion, Scudder et al (1990) again indicated that the Critical Ratio rule results in a higher net present value than the other three dispatching rules investigated in their study. In another study, Rohleder and Scudder (1992) compared 10 different time-based dispatching rules. They showed that the Critical Ratio rule is consistently ranked in the group of rules which has the highest mean job net present value.…”

Scheduling with forbidden early shipments: alternative performance criteria and conditions

“…For MAD and Tat the tight settings, MOD performs the best. This result is consistent with past research for T, but given that MOD is not in the top group for NPV, it is surprising that it would perform well on Downloaded by [New York University] Figure 5, Performance of rules for various production environments, MAD, However, it makes sense when we consider that MAD is an overall measure of how closely job completion matches the established job due date, Thus, MAD does not account for the value of WIP inventory, but only considers the effects of finished goods inventory, Note that MAD could be quite small, but operations could be started far earlier than necessary, thereby increasing WIP levels without affecting finished goods levels, Schudder and Rohleder (1992) showed that MOD started operations earlier than most other dispatch rules and incurred greater inventory costs, So, although it does well in meeting the overall due date for MAD, its tendency to start operations too early hurts its N PV performance, At the low utilization level and relaxed allowance setting, MDD is not in the top group for N PJI, as it was at the high/relaxed setting, This is due to an interaction with the dynamic allowance method and immediate release settings of the decision Downloaded by [New York University] factors. This was one of the rare times where the specific treatments needed to be considered for complete analysis.…”

“…This problem has been examined in part in Kanet and Christy (1989), Scudder and Hoffmann 2288 G. D. , and Rohleder and Scudder (1992). This previous research has considered a variety of different issues in a piecemeal fashion, with little or no integration of many important issues.…”