Modeling approaches corresponding to the layers

• Material flow layer
  • transaction-based modeling
  • abstract entities (e.g. workpieces or tools)
  • move between stationary components (here: production facilities)
• Process control layer
  • modeling of process logic with state graphs
  • alternatively transaction-based modeling
  • entities = abstract control tokens
• Process physics layer
  • physical laws (mechanics, thermodynamics etc.) → ODEs
  • physical modeling approach → DAEs
• Concrete simulation programs
  • coupling of DES program with continuous simulator
    • e.g. PlantSimulation + Simulink
    • cumbersome, slow
  • coupling of DES program with existing FEM model
    • slow, level of detail too high
  • hybrid modeling combining different paradigms
    • used here: Simulink + SimEvents + Stateflow + Simscape
    • alternative: Modelica + several extra libraries