How is diadakan both procured and held? What is the literal meaning in English? as it seems to fall in-between words. Perhaps it is more like put together?
"Ada" means exist. So "diadakan" is "being made to exist".
should it be dihasilkan instead of diadakan?
Not in this context. "Dihasilkan" is more similar to "produced" in meaning, than to "procured".