Machine Scheduling

We currently have only generators for the Identical Parallel Machine Scheduling problem. The problem is to determine a schedule of n independent jobs on m identical parallel machines without preemption, (n>=m>=2). In literature this problem is called, using the three-fields notation, P||Cmax.

Here is the list of all random generators for Machine Scheduling instances available from this site.

All instances are packed with “tar” and compressed with “gzip”: these are ubiquitous on unix systems, and available for essentially every other architecture. Once a file f.tar.gz has been downloaded, it must be first decompressed (gzip -d f.tar.gz under unix) and then un-tarred (tar xvf f.tar under unix) to retrieve the original files and/or directories. Files f.tgz are compressed directly within tar, and can be dealt with the unique command “tar xzvf f.tgz”.


PIMSGen

PIMSGen is a random generator for (P||Cmax) Identical Parallel Machine Scheduling instances.

To use the generator, get the file PIMSGen.tgz: it contains a directory PIMSGen. The directory PIMSGen contains the source code for the generator, a batchfile named genfiles to build the executable and to create all instances and a README for further information.


Gera

Gera is a collection of four random number generator of (P||Cmax) Machine Scheduling instances, obtained by Felipe Martins Muller. In this collection you can find:

  • geraun – the integer random number generator for uniform instances.
  • geran – the normal distribuition generator.
  • gerae – the exponential distribuition generator.
  • gernum – with this generator you can yield instances with real processing times either with gaussian distribution or with unifrom distribution.

To use the generators, get the file Gera.tgz: it contains the directory Gera. In that directory you can find the source code for the generators (gerae.c, geran.c, geraun.c, gernum.c) and a Makefile to build the executable (just typing make). More information can be found in the file README.