Moving equipment from one place to another,usually requires revalidation .Revalidation is needed to ensure that changes in the process or in process environment do not adversely effect process characteristics and product quality.when equipment is moved to a new location installation and operation should be re-qualified.By comparing data with original IQ and OQ,the manufacturer can determine whether there have been any change in equipment performance as a result of move.changes in equipment performance should be evaluated to determine when it is necessary to revalidate the process.