Determine frequency type production count

If a sample plan frequency is configured to generate future samples for a production count frequency—that is, the sample plan frequency type is Production—and the frequency is configured to count individual units, the active QM specification using this frequency generates future samples either to the end of the shift or the time specified in the future sample generation property. For samples to be generated for this frequency, a job must be running on the entity.

The job’s production rate is used to estimate the time when future samples will be generated. For example, a production unit count frequency of every 50 units in effect when a job with a production rate of 10 batches per hour and a batch size of 20 units per batch will create future samples 15 minutes apart (for additional information about batch size, see Understand batches and lots for OEE and estimated times).

50 units / (10 batches/hour * 20 units/batch) * 60 minutes / hour = 15 minutes

Samples will be predicted when the job starts on the entity and any remaining future samples will be deleted when the job stops. Future samples will be predicted to the end of the shift if there is no Future sample generation setting; otherwise, samples will be generated up to the "future sample generation" interval. In either case, samples will be predicted to cover only the starting quantity of the job plus one additional sample for over production. Using the above frequency example, if a job is started with a start quantity of 225 units, then 5 samples will be generated every 15 minutes apart. If the Future sample generation setting is 0, then no future sample are generated and the frequency behaves as an event frequency generating samples with the production of a sufficient quantity of units.

Unlike the calendar and shift frequencies, future production unit count samples are readied only when the required number of units have been produced instead of based on the future sample request time. Both good and bad counts of production are considered when readying a sample. As production counts are recorded against the job, the total is maintained in a context table in the database. This includes when the production quantity is reduced. When a production transaction causes the total to equal or exceed the frequency interval units, then the next available future sample will be readied by the MES middleware maintenance service during the next update of sample status. This might take up to the time period specified by the system parameter Frequency to call sample updates (in seconds), which has a default of 30 seconds.