Before revision: Validation is the process of establishing documentary evidence demonstrating that a procedure, process, or activity carried out manually or through computer system in the stages of dispensing, manufacturing, final packing, distribution and testing of intermediate stages and finished goods stages during production , testing, and their computer system operation is able to or not able to maintain the desired level of compliance at all stages.
After revision: Validation is the process of establishing documentary evidence demonstrating that a procedure, process, or activity carried out in testing and then production maintains the desired level of compliance at all stages.