Abstract: This paper examines a supply planning problem for multilevel serial production systems under lead time uncertainties. The techniques used in industry are often based on the assumption that the lead times are known. However, in a supply chain the lead times are often random variables. Therefore, it is necessary to evaluate the influence of the planned lead times on the total cost. An e...

Scheduling a sequence of tasks — in the acceptation of finding the execution times — is not a trivial problem when the optimization criterion is irregular as for instance in earliness-tardiness problems. This paper presents an efficient Dynamic Programming algorithm to solve the problem with general cost functions depending on the end time of the tasks, idle time costs and variable durations al...

We present a novel model for due date quotation. Jobs arrive at a single server or m-machine flow shop over time. Upon arrival, the processing times on each machine of the job are known, and due dates must be quoted for each job. The jobs are sequenced on the machines without preemption. Associated with each job, there are three measures of disadvantages to the inventory cost and the service le...

This paper considers a scheduling problem for a single burn-in oven in the semiconductor manufacturing industry where the oven is a batch processing machine with restricted capacity. The batch processing time is set by the longest processing time among those of all the jobs contained in the batch. All jobs are assumed to have the same due date. The objective is to minimize the sum of the absolu...

This paper deals with the problem of ,nding a minimum cost schedule for a set of dependent activities when a convex cost function is attached to the starting time of each activity. A ,rst optimality necessary and su/cient condition bearing on the head and tail blocks of a schedule is ,rst established. A second such condition that uses the spanning active equality trees of a schedule leads to de...

In this paper, we address the problem of load selection and pickup-dispatching of multiple-load AGVs. Various load-selection rules and pickup-dispatching rules are proposed and studied. The objective of this study is twofold. We want to understand not only the performance of load-selection rules and pickup-dispatching rules in two performance criteria—throughput and tardiness, but also the effe...

The General Scheduling Problem (GSP) generalizes scheduling problems with sum of cost objectives such as weighted flow time and weighted tardiness. Given a set of jobs with processing times, release dates, and job dependent cost functions, we seek to find a minimum cost preemptive schedule on a single machine. The best known algorithm for this problem and also for weighted flow time/tardiness i...

The unrelated parallel machine scheduling (PMS) problem is essential for the manufacturing industry. Scheduling will save company resources, especially time management. By solving problems quickly and precisely, can get more profit. On that note, this paper focused on PMS problems, which did not consider inherent uncertainty in processing set up by minimizing makespan tardiness. This aimed to m...

This study investigates the single-machine scheduling problem with common due-win -dow assignment, past-sequence-dependent (p-s-d) setup times and a deteriorating maintenance activity. By past-sequence-dependent setup times, we mean that the setup time of a job is proportional to the sum of the processing times of the jobs already processed. The objective is to minimize a cost function based on...

We consider uniform parallel machine scheduling problems with unit-length jobs where every job is only allowed to be processed on a specified subset of machines. We develop efficient methods to solve problems with various objectives, including minimizing a total tardiness function, a maximum tardiness function, total completion time, the number of tardy jobs, the makespan, etc.