Thankyou all for the replies. Judging from what you three have said, i reckon 30 should be enough for one to find some form of saturation .

While transcribing is indeed pain-staking, doing it yourself really does get you closer to the data. Infact i find transcribing and making notes and coding should preferably be happening all at once

Just wanted to know how many interviews you're thinking of doing in your PhD if this is your adopted form of data collection. I am intending to do between 20-30 by 2hrs. Does that sound robust? I know it depends on a variety of other factors like research issue, point of saturation, etc. However surely there must be a suggested range somewhere. For example how many cases is required for a Phd? Many would say 'how long is a piece of string', however Eisenhardt suggests 4-10 is reasonable regardless.

Many thanks

Is the 'case-study method' widely accepted as a methodology for a PhD in the business faculty?
What is the appropriate number of cases required in a PhD thesis?
Any sites/references/structure for writing up the methodology section using case-study approach?