1. Document the situation
Gather the job description, the employment contract, pay slips, and, if available, the job advertisement with the pay range. Briefly write what you actually do at work (responsibilities, decisions, workload) and the relevant data of your career in the company (since when you have held the position, what changes have occurred). The aim is not to collect colleagues' salaries (these are confidential), but to build a clear picture of your role and the pay received in relation to the responsibilities of colleagues of the opposite sex in comparable positions.