Optimization and Scheduling Toolbox

Abstract

TORSCHE (Time Optimization of Resources, SCHEduling) Scheduling Toolbox for Matlab is a freely (GNU GPL) available toolbox developed at the Czech Technical University in Prague. The toolbox is designed for researches in operational research or industrial engineering and for undergraduate courses. The current version of the toolbox covers the following areas: scheduling on monoprocessor/dedicated processors/parallel processors, open shop/flow shop/job shop scheduling, cyclic scheduling and real-time scheduling. Furthermore, particular attention is dedicated to graphs and graph algorithms due to their large interconnection with the scheduling theory. The toolbox offers a transparent representation of the scheduling/graph problems, various scheduling/graph algorithms, a useful graphical editor of graphs, interfaces for mathematical solvers (Integer Linear Programming, satisfiability of the boolean expression) and an interface to a MATLAB/Simulink based simulator and a visualization tool. The scheduling problems and algorithms are categorized by notation (α|β|γ) proposed by Graham and Blazewicz (Blazewicz et al., 1983). This notation, widely used in the scheduling community, greatly facilitates the presentation and discussion of scheduling problems. The toolbox is supplemented by several examples of real applications, e.g. the scheduling of Digital Signal Processing (DSP) algorithms on a hardware architecture with pipelined arithmetic units, scheduling the movements of hoists in a manufacturing environment and scheduling of light controlled intersections in urban traffic. The toolbox is equipped with sets of benchmarks from the research community (e.g. DSP algorithms, the Quadratic Assignment Problem). TORSCHE is an open-source tool available at (http://rtime.felk.cvut.cz/ scheduling-toolbox/) In the off-line scheduling area, some tools for the development of scheduling algorithms already exist. The term off-line scheduling means all parameters of the scheduling problem are known a priori (Pinedo, 2008). A scheduling system developed at the Stern School of Business is called LEKIN (Pinedo et al., 2002). It was created as an educational tool and it provides six basic workspace environments: single machine, parallel machines, flow shop, flexible flow shop, job shop, and flexible job shop. Another tool is LiSA (Andresen et al., 2003). It is a software-package for entering, editing and solving off-line scheduling problems while the main focus is on shop-scheduling and one-machine problems. The graphical user interface is written in Tcl/Tk for machine and operating system independence. All algorithms are implemented externally while the parameters are passed through files. The commercial tool ILOG Scheduler from the software package ILOG CP Optimizer (ILOG, 2009) is based on 12