Usage patterns
人事を発表するto announce personnel changes/appointments
The company announced next month's personnel changes.
人事が決まるfor personnel assignments/decisions to be finalized
The appointment of the new department head has been decided.
〈人〉の人事を担当するto be in charge of someone's personnel matters
She is in charge of personnel matters for this department.
Expressions
人事を尽くすdo everything humanly possible; exhaust all means