Supervisors can set general goals for the work group and specific goals for individual employees.
Whenever possible, express these goals in numbers for maximum objectivity. Numerical goals leave no debate about whether they were met. If you involve them in setting goals, they'll be more likely to support those goals as a team instead of as a collection of individuals. When you give employees a vested interest in setting goals, they tend to work for themselves as well as for you. Enlightened self-interest can be a powerful motivator.