The oil extraction rate (OER) represents how much CPO can be extracted from the palm fruits. It Palomid 529 therefore commonly used to indicate the performance of the mills. A higher %OER is preferred because of a lesser FFB is needed and a lesser waste is generated. In the P-RSPO mills, %OER is calculated at 16, which is lower than for the other cases (17% for the N-RSPO mills and 18% for the C-RSPO mills). This leads to the highest FFB input (6.44 t FFB) and the highest waste generation (1376 kg EFB/t CPO, 780 kg fiber/t CPO, and 218 kg decanter cake/t CPO). Technicians in the P-RSPO mills revealed that the price of FFB largely depends on its weight but not its quality so that smallholder farmers seem to neglect the quality of FFB. In addition, poor management by middlemen, such as watering on palm fruits and mixing up with sand, was observed to increase the weight of FFB. Quality of FFB is, therefore, an urgent and important issue that need to be addressed by relevant stakeholders (i.e. farmers, millers, middleman, and government) as countercurrent flow can reduce %OER and, as a result, the waste-related problems (cf. Dallinger (2011)).