In this paper, we consider the problem of scheduling on two-machine permutation flowshop with minimal time lags between consecutive operations of each job. The aim is to find a feasible schedule that minimizes the total tardiness. This problem is known to be NP-hard in the strong sense. We propose two mixed-integer linear programming (MILP) models and two types of valid inequalities which aim t...

This paper deals with the non-permutation flowshop problem which means that the job sequences are allowed to be different on machines. The objective function is minimizing the total tardiness. Firstly, three mixed-integer linear programming (MILP) models for non-permutation flowshop problems are described, and then are analyzed and assessed their relative effectiveness. Secondly, two Tabu searc...

This paper deals with the permutation flowshop scheduling problem time lags constraints to minimize total weighted tardiness criterion by using Branch and Bound algorithm. A new lower bound was developed for problem. The computational experiments indicate that proposed algorithm provides good solution in terms of quality requirements.

We combine mixed integer linear programming (MILP) and constraint programming (CP) to minimize tardiness in planning and scheduling. Tasks are allocated to facilities using MILP and scheduled using CP, and the two are linked via logic-based Benders decomposition. We consider two objectives: minimizing the number of late tasks, and minimizing total tardiness. Our main theoretical contribution is...

In this paper, we propose different local search algorithms to solve a realistic variant of the flowshop problem. The variant considered here is a hybrid flexible flowshop problem with sequence-dependent setup times, and with the objective of minimizing the total tardiness. In this variant of flowshop, stage skipping might occur, i.e., not all stages must be visited by all jobs. This scheduling...

In this paper, we are discussing a research project aiming to optimize the scheduling of production orders within real application in packaging field. As first approach, model problem as an extended version hybrid and flexible flowshop with precedence constraints, parallel machines, sequence-dependent setups. The optimization objective considered is minimization total tardiness. To tackle probl...

We consider the problem of n-jobs scheduling in an m-machine permutation flowshop with exact time lags between consecutive operations of each job. The exact time lag is defined as the time elapsed between every couple of successive operations of the same job which is equal to a prescribed value. The aim is to find a feasible schedule that minimizes the total tardiness and earliness. We propose ...

The two-stage assembly flowshop scheduling problem is addressed with the objective of minimizing total tardiness. An insertion algorithm, a genetic algorithm, and a hybrid of the insertion and genetic algorithms, are developed for the problem. Conducted computational experiments reveal that the hybrid algorithm significantly outperforms the genetic algorithm while the best performing algorithm ...

Scheduling problems involving both earliness and tardiness costs have received significant attention in recent years. This type of problem became important with the advent of the justin-time (JIT) concept, where early or tardy deliveries are highly discouraged. In this work we examine the flowshop scheduling problem with no storage constraints and with blocking inprocess. In this latter environ...