You don't need to worry about having multiple versions of the same thing when you log into your work area in the Repository as this is actually a requirement of the system in order for the Repository to talk to TULIP, and therefore to your Portfolio of Activitiy, staff profile, etc. We can use a metaphor to explain this, namely that the repository and TULIP are on opposite sides of a river, and data has to get from the Repository, over the river and into TULIP.
Each time you create a version of a record you’re creating an extra stepping stone between the riverbanks, and also widening the river – each stepping stone, or in other words each version of the record, is always one full stride apart. If you were to remove one of those stepping stones by deleting one of the versions you would break the path and make it impossible for data to get from the Repository into TULIP, i.e. your record would fall into the metaphorical river.
That is why no-one is able to delete previous versions of a record from their manage deposits area in the Repository. This is italicised as it's important to note there will still only ever be one version of the item publicly available for outside users to view, so you needn’t worry about staff profiles, the public view of the Repository, etc., getting cluttered up with multiple versions of the same thing.