Verification is proving that a system element or the system as a whole meets the requirements imposed on it. Test is one method to gather data for such proof. Other methods include analysis and inspection. Since test is an integral part of most verification processes, they are normally grouped together. Verification and test is normally applied at multiple levels of a design, starting at the component level and working up to the complete system. This is to discover problems at the lowest level possible, where it is easier to identify the cause. If lower level problems are resolved, any problems that occur at the next level of integration are likely to be from the integration of multiple components itself.