SKU Numbers
Definition
SKU numbers are a piece of information that uniquely identify every model of parts that a machine can produce.
For example, if a factory uses the same machine to produce forks and spoons, then "Forks" and "Spoons" could be logical SKU numbers for this machine.
The image below shows the configuration of a machine that is used to produce forks and spoons.
At any given time, using the Machine State tile, the operator of the machine can then specify if they are producing forks or if they are producing spoons. The image below shows us that Bob is currently using the machine to make forks.
Unit completion time
SKU numbers must also be provided with a unit completion time, which is the time that it normally takes to produce one unit of that type. For example, if a machine can produce 6 forks in one hour, the unit completion time for forks on this machine is 10 minutes. Unit completion time is needed to calculate the performance of a machine, so that the application, given a time span and a number of input parts, knows if the machine is producing at the rate it is supposed to produce.
If you are measuring performance and you notice that it is over 100%, it could be because the unit completion time defined for some of your SKU numbers are too high and should be lowered. The unit completion time should be a theoritical maximum.
Number of signals per part
The number of signals per part is an option that you can activate by SKU number in the special case where the part creation rule needs to be triggered multiple times for a unit to be created. For example, let's take a machine that attaches panels to a structure. The machine needs to install 4 screws to put the panel in place before moving on to the next one. If we want to follow the production of this machine, we will have to create a "part" each time a panel is fixed. On the other hand, if we only have a signal on the screws that are put in, and not on the panels, we need a way to say that a panel is created only after the fourth screw is put in. This is where the number of signals per part option comes in handy.
In the example given above, the number of signals per part would be 4 and can be configured differently in input and output if necessary. If not specified, it is 1 by default.