From your sharing, your employee may have other concern at work, not only bonus scheme, but also process, quality, skill, capacity... Different people, different motivation. then we need to understand their nich and desire to provide the suitable support to increase the productivity.
I have been working in human resource management over 6 years, taking charge of lots of employee survey (engagement survey, productivity survey...). That project fits to my experience and expertise.
Looking forward to our cooperation.
Thanks,
Thu