This paper calls for a change in paradigm in lot sizing and scheduling. Traditionally, a discrete time scale is chosen to model lot sizing and scheduling. As an alternative, the so-called block planning concept is proposed which is based on a continuous representation of time. A mixed-integer...

We establish the computational complexity of the problem of minimizing makespan in a flowshop, where each jobs requires a pallet the entire time, from the start of its first operation until the completion of the last operation. We prove that the problem is NP-hard in the strong sense for m =2...

Scheduling methods are proposed for a class of flexible manufacturing systems consisting of machine centers served by a cyclic conveyor. The minimization of finish time is considered as the optimization criterion. An optimal algorithm is proposed for the minimum conveyor speed (S = 1) for a...

The optimal production control problem of deterministic pull flow lines with multiple part types is considered in this paper. The last machine is assumed to be the bottleneck. The objective is to minimize the total inventory and backlog costs over time. We give an optimal production policy and...

Parallel machine structure is very common in modern production systems. Its performance sometimes has a decisive impact on the whole productivity. In this paper, we consider a parallel-machine scheduling problem where each machine is subject to periodic maintenance. Instead of assuming all the...

Job shop scheduling with a bank of machines in parallel is important from both theoretical and practical points of review. Here we focus on a flexible job shop scheduling problem of minimizing the makespan in a two-center job shop, where the first center consists of one machine and the second...

Flow shop scheduling is common in modern lean production systems. In practice, jobs in flow shops can arrive at irregular times. However, scheduling that considers such irregularity has not been adequately investigated in the literature. In this paper, we examine the scheduling of n-jobs in an...

This paper presents a simple Optimised Search Heuristic for the Job Shop Scheduling problem that combines a GRASP heuristic with a branch-and-bound algorithm. The proposed method is compared with similar approaches and leads to better results in terms of solution quality and computing times

The paper is concerned with the problem of optimal production planning in deterministic pull flow lines with multiple products. The objective is to specify the production policy that minimizes the total inventory and backlog costs overtime. Assuming constant product demands and non-decreasing...