Dynamic flexible job shop scheduling problems has been one of the important and strongly NP-hard problem of manufacturing systems for many years. Most of the proposed algorithms are based on priority rules; By using these rules, the arrived jobs go to a long queue of waited jobs and sometimes it takes a long time for a job to be processed. In this paper a new approach, integrating of priority r...

The Flexible Job Shop scheduling Problem (FJSP) is a generalization of the classical Job Shop Problem in which each operation must be processed on a given machine chosen among a finite subset of candidate machines. The aim is to find an allocation for each operation and to define the sequence of operations on each machine so that the resulting schedule has a minimal completion time. We propose ...

The flexibility present in a job shop is an important determinant of the future success of the shop, since it increases the ability to deal with the changes a job shop is faced with in a dynamic environment. The presence of idle-time in a job shop schedule contributes considerably to this flexibility. By introducing an anticipation factor that preserves idletime in the scheduling process more f...

In the classical job shop scheduling problem (JSSP), n jobs are processed to completion on m unrelated machines. Each job requires processing on each machine exactly once. For each job, technology constraints specify a complete, distinct routing which is fixed and known in advance. Processing times are sequence-independent, fixed, and known in advance. Each machine is continuously available fro...

This research will analyze and discuss the inner behavior of a flexible manufacturing cell in order to buildup its object-oriented simulation system. An object-oriented Petri Net will be built to model a flexible manufacturing cell. The objects of the object-oriented Petri Net are directly mapped from physical objects of a flexible manufacturing cell. This cell includes a robot, several machine...

In simple flow shop problems, each machine operation center includes just one machine. If at least one machine center includes more than one machine, the scheduling problem becomes a flexible flow-shop problem. Recently, group scheduling has also been proposed and discussed. In the group scheduling, each job belongs to a specific group and all the jobs are processed group by group. In this pape...

Using a large linked employer-employee data set, this paper studies the relationship between job reallocation, worker reallocation and the flexibility of wages in western German manufacturing. Using the plant-specific residual wage dispersion as a proxy for wage flexibility, we find that more flexible wages are associated with less job reallocation due to demand shocks being absorbed by wage ra...

OBJECTIVES In a job site, a portable fan is often used to ventilate a confined space. When a portable fan is applied to such a space, the actual ventilation flow rate must be accurately estimated in advance because the safety level of contaminant and oxygen concentrations in the space will determine the ventilation requirements. When a portable fan is used with a flexible duct, the actual flow ...

Functionally flexible systems for organizing work may reduce job instability and insecurity by reducing employers’ reliance on job cuts or contingent work to respond to changes in their environments. Related arguments hypothesize that contingent work allows firms to adjust labor while “buffering” their core of permanent workers from job instability. We find evidence that internally flexible wor...

The recent manufacturing environment is characterized as having diverse products due to mass customization, short production lead-time, and unstable customer demand. Today, the need for flexibility, quick responsiveness, and robustness to system uncertainties in production scheduling decisions has increased significantly. In traditional job shops, tooling is usually assumed as a fixed resource....