How is the same work defined? By the National Classification of Occupations and Positions, by hierarchical level or job grade within the company?

The same work should be assessed comprehensively, not only on the basis of a job description or code under the National Classification of Occupations and Positions. The classification code may serve as a starting point, but the decisive factors are the job functions actually performed, the responsibilities, complexity and degree of independence. Employees with the same classification code may perform work that differs in substance. For example, an accountant who mainly records invoices and an accountant who participates in audits and inspections, prepares opinions and carries broader responsibility may have different work content.