134
5 Development of a Simulation-based Methodology …
running machine for the processing of new raw material parts instead of starting
another machine. The ‘select machine function’ is checking the status of machines
before the raw material is assigned for processing (Figure 5.32). In case of the
CNC1 and CNC2 the function checks the following cases: if both machines are
in off state, the throughput time estimation is used to calculate which machine
is available faster to serve the production schedule best in case parts need to be
processed. Is CNC1 already producing and new raw material is available, machine
CNC2 will be started and vice versa. The last check covers the case that CNC1
and CNC2 are already running and new material needs to be assigned to one of
the two machines. Here, the ‘select machine function’ compares the buffer sizes
and assigns the material to the machine with the lower buffer stock.
Function
Figure 5.32 ‘Select machine function’ logic
To avoid an early machine start of those machines, that are not required during
the first production steps, an automated calculation to determine the remaining
time until a machine has to be ready for production is added to the model. By
defining a so-called ‘throughput time estimation function’, the time is determined
5 Development of a Simulation-based Methodology …
running machine for the processing of new raw material parts instead of starting
another machine. The ‘select machine function’ is checking the status of machines
before the raw material is assigned for processing (Figure 5.32). In case of the
CNC1 and CNC2 the function checks the following cases: if both machines are
in off state, the throughput time estimation is used to calculate which machine
is available faster to serve the production schedule best in case parts need to be
processed. Is CNC1 already producing and new raw material is available, machine
CNC2 will be started and vice versa. The last check covers the case that CNC1
and CNC2 are already running and new material needs to be assigned to one of
the two machines. Here, the ‘select machine function’ compares the buffer sizes
and assigns the material to the machine with the lower buffer stock.
Function
Figure 5.32 ‘Select machine function’ logic
To avoid an early machine start of those machines, that are not required during
the first production steps, an automated calculation to determine the remaining
time until a machine has to be ready for production is added to the model. By
defining a so-called ‘throughput time estimation function’, the time is determined