Regularly scheduled and properly documented inspections also provide important long term information, identifying positive and negative trends that otherwise would not be noticed. For example, comparisons across time can reveal persistent problems with an unsuspected cause or could show whether safety standards are improving or deteriorating over time.
Inspections provide a measure - on a formal, ongoing basis as well as on a planned and formal basis - because you're a legally and morally obligated to ensure safety in the workplace. The results can help you determine what needs to be done in terms of training, enforcement, and supervision.
With proper recommendations for corrective action, and follow-up, inspections can be the key to maintaining the highest possible safety standards.