Administrating your payroll in a way that you pay for each piece produced (that is you pay to your workers say 1 CU for each item that they’ve produced during the period they get paid for, i.e. a week if you apply a weekly wage) means first off that you have people doing manual labor, that is, you have employees who produce goods. There’s nothing wrong with that, but more of stating the fact here. 

Regardless, once you’ve determined that instead of paying an hourly wage you’ll apply a work by the piece system, you’ve also got to come up with controls over the amounts of pieces people produce. Note here that work by the piece also inherently means that your employees still get paid either once a week or a month. Regardless of their pay method (i.e. hourly wage or work by the piece) they are required to be paid regularly in that sense.

Understanding the risks arising from paying people for the amount of pieces they’ve produced means that you can also come up with essential and effective controls over those amounts. It’s not only amounts however, but also the quality. Someone may be working really hard but still doing a lousy job and manufacturing goods that cannot be sold for instance. So there has to be a quality control as well of the produced items. Yes, you’d have it nonetheless I would presume, however do consider implementing quality as well into the payment system when paying for pieces produced.