1. Graduate Programming in Computing Federal University of the Rio Grande do Sul (UFRGS) Porto Alegre 91 501‐970 Brazil
2. Department of Production Engineering Federal Fluminense University Petrópolis 25 650‐050 Brazil
3. Industrial Technical College Federal University of Santa Maria Santa Maria Brazil
4. Department of Production Engineering Federal University of São Carlos (UFSCar) São Carlos 13 565‐905 Brazil