It sounds like you would have a comparative case study of two different industries. Whether or not 6 interviewees would be enough in either case would be almost impossible for you to judge until you start doing your interviews. In particular, if the participants give you very different responses, then you will need to interview more people in order to understand the reasons for that diversity.

If you do need to do more interviews, one possibility would be to get further recommendations from the people you do interview (i.e., "snowball sampling").

It sounds like you would have a comparative case study of two different industries. Whether or not 6 interviewees would be enough in either case would be almost impossible for you to judge until you start doing your interviews. In particular, if the participants give you very different responses, then you will need to interview more people in order to understand the reasons for that diversity.

If you do need to do more interviews, one possibility would be to get further recommendations from the people you do interview (i.e., "snowball sampling").

I agree with David's answer, and I would add that it really depends on how your thesis advisers see what is "enough" in numbers. There is no rule as such for qualitative research

Hi,

Like the previous colleagues argued, you will not know for sure whatever the number of interviews is sufficient beforehand. If during the 5th pair of interviews you will hear about the things largely similar to those obtained in the previous interviews and the 6th pair will not add much new information, your job will be done. If any new pair will inform you about new surprising things, you must continue the series of interviews.

I agree with what the previous colleagues said.

I believe that, in your case, two levels should be considered.

The first level consists of methodological aspects. In QL research is better to achieve saturation of data. This means that you can stop collecting data when you find data that sounds redundant. I don't know your research question in details, so I can't be able to establish if 6 is enough for each organizational sector. Moreover, it depends on how much is crucial to deepen the peculiar aspect of each organization. If it is not important, one member of each company could be sufficient.

Instead, the second level deals with the limits and resources that you have. You can have constraints that do not allow you to interview more subjects (time, access to other organizational context, etc.). I think you should discuss this aspect with your advisor and find a shared solution.

Thank you all, this has been very helpful!

Good question, I am looking at responses.