It looks like the customer has form for incomplete hr projects. Usually there is blame on both sides in these situations. Client doesn't give clear requirements, supplier doesn't hold them to provide them, standard application "best practices" only work for the guys in the application developer team and not in real life. Clients also hate changing the way they have always done x and find any excuse to not simplify or improve their practices.
Good luck Maine with your next attempt to implement HR and finance systems.