The booming progresses of machine vision is very well reflected by the amount and the quality of the papers that are published weekly on that topic. The rate of introduction of machine vision on the shop floors is far less impressive. Resistance to change should not be invoked exclusively to explain that paradoxical situation. Central to that problem, is the communication gap between the hi-tech experts, who propose dramatically new solutions to traditional problems, and the production managers, too exclusively concerned with their sole production technologies. The focus of this paper is on inspection and control. Guidelines are provided - to identify the most promising applications for machine vision, inside a manufacturing plant, - to evaluate them versus human inspection and - to compare the various advantages and limitations of the currently available systems.