"to make it work" means 1- to do anything in your power to make a project succeed. 2- to make something work properly. -We have to complete this work by tomorrow. Don't worry, we'll make it work by the deadline! - You may even use it as a slogan: "Make It Work, Make It Right, Make It Fast."

To make something work means to make it function properly. It can be something physical (a clock, for instance) or something more abstract (a friendship, a relation, for instance).