question

You can actually combine all the Statistics Collectors you have into a single Statistics Collector, with the four columns (quality, performance, availability, and OEE). When a Statistics Collector updates, it evaluates columns from left to right in the table, for each row. The internal object "data" is not reset between columns, so you can assign values to data in one column, and use it in the next column:

For the Quality column, you can use something like this in the Value code:

double quality;
// ... calculate quality
data.quality = quality;
return quality;

The same is true for the Performance and Availability columns:

double performance;
// ... calculate performance
data.performance = performance;
return performance;

double availability;
// ... calculate availability
data.performance = availability;
return availability;

Then you can use this code in your OEE column:

data.quality * data.performance * data.availability

Again, this only works if all four columns are always columns. Here is a demo model I made a while back that uses this technique:

oeedemo.fsm