**4.4 Model evaluation and validation**

Basically, at this stage, testing or validation is carried out about has the model produced logical outputs in common sense and is in line with the real world or existing facts, are the existing relationships are logical, are the model's behavior is in accordance with expectations or goals. Model design, are the model outputs appropriate or very close to the field data, and so on. Some of the references that will be used are OPP references that have received ISPO and/or RSPO certification, as well as for OPP which are considered to be reference plantations that are very well managed.
