Personnel certification bodies assess the competency of people: electrical engineers, career advisers, welders, inspectors, etc. It starts with an analysis. What type of job does a person have? What are the associated tasks? What skills are required? A personal certification body then examines how the competencies can be tested, for example via exams, assessment or a work piece. In the event of a positive result the relevant person is issued with a certificate. The major difference between this and a diploma is the certification involves ongoing supervision. A certificate therefore has a specific period of validity.