We propose monitoring of software components, and use of monitored software components, as a general approach for engineering of embedded computer systems. In our approach, a component's execution is continuously monitored and experience regarding component behaviour is accumulated. As more and more experience is collected the confidence in the component grows; with the goal to eventually allow certification of the component. Continuous monitoring is also the base for contract checking, and provides means for post-mortem crash analysis; an important prerequisite for many companies to start use 3rd party component in their dependable systems.In this paper we show how four software engineering goals can be reached by monitoring four component properties.