Are you interested in the history of how cycle time has changed over the years? There have been plenty of case studies in specific organisations but I don't recall seeing any industry-wide surveys.
There are lots of variables. The expectation is usually that cycles get shorter over time and I see 5 days or less being normal in organisations I work with, compared to maybe 15 days a decade ago. I too would be interested to know if anyone has more comprehensive data. Saving Changes...
Which cycle time are you referring to? An individual requirement's completion time from it being started to done or a product release? This will also vary widely by industry and type of software.
