Your grading as an NWO-I employee depends, in part, on your position. The Collective Labour Agreement Research Institutions states: "from the nature and level of the job".
In practice, this means that for each job, a description applies, and for each job (description), a job grade is determined in a prescribed manner. The job level is a salary scale. It is the salary scale in which NWO-I places a person who fully realizes the job.
At NWO-I, determining the level, the so-called job grading methodology has been based on the Job Level Matrix since 1 July 2003.
You can inspect the Job Level Matrix and the reference positions that are part of this in the book of job descriptions (approved 2019) for positions at NWO-D, the NWO-I Office, and the operations positions at the Institutes. This is possible at the P&O Departments of the Institutes and the NWO-I Office.
If you do not agree with the job description applicable to you, then within two weeks you can contact your P&O Department for a meeting with them and your line manager about this.
If this meeting does not lead to an appropriate solution, then within two weeks after that meeting you can submit a written request for a reconsideration of your position to your institute director. After you have been informed about the outcome of that reconsideration, then you still have the option of Right of complaint employer NWO-I (IR-11).