Why do OPEC members always disagree on how much oil should be produce for each country/member?

Since this is your homework. Tell us what you think the answer is and why. And we can comment on that.

Clearly you aren't suited for the course you are taking. You won't tackle a single question on your own. All the questions you have asked here are too broad for online answers. We help you through problems you have done the work on but are just stuck in one little place.