After contacting one of Adobes consultants, we solved the problem.
What happens? If a customer (profile) appears in more than 1 segment, the output with the current configuration places the customer in 1 segment. When a customer should be in segments 2, 3 or 4 i've to turn 'enable overlapping of outbound populations' on.
After turning this option on:
the result is ok (610 records in, 610 records out)
Normally the target has to be unique. But in this case, it didn't have to be, because all segments contain different content.
So always check carefully if customers really have appear more than once in your output, using this option in the segmentation.
I've checked if I had any filters or limitations in my segmentation, but I had none.
I can't imagine that the complement function in a segmentation doesn't contain all remaining records. Because that's the reason why I generate a complement 😀
The query in the segmentation is based on a combination of fields: 'verlengingsdatum (date)', 'aflosdatum (date)', 'verlengings_dt_2 (date)'. I added an extra segment, to make sure the complement should be 'zero'.
I've imported the data file once again in a Load File and the problem still exists. I added a new load file to ensure this.
Still the segmentation starts with 610 records (containing 431 unique customers or profiles). But only 605 records are exported towards the union. Although the combinations of columns are unique, a few customers are filtered in the output and appear only once, instead of two or three times.
I've selected these customers, based on their profile in a new segmentation (number 8). After that all records are visible in the audience.
I don't understand why some records are missing in my output.
Usually count difference in segmentation outcome happens, if we don't have proper filtering criteria. For example, if i want to get a list of profiles belongs to business named "Consumer" from the transition. You can maybe think of having one segmentation with filtering criteria as Business is equal to "Consumer" and remaining can go as complement. But sometimes this will not work properly.
To achieve this will use one segmentation filtering as Business is equal to "Consumer" and on another segmentation filtering criteria would be Business is not equal to "Consumer" and Business is not empty. Here generate complement won't be used.
If you can adjust the filtering criteria for segmentation activities that will give you expected count you're looking.
Still if you're not getting the expected count then would it be possible to share the segmentation6 & 7 activities filtering criteria.