handling multiple parallel releases

[Sandeep Bhatnagar]

Hi,

I am leading a team working on multiple (more than 3) releases, work
for which goes on in parallel. There are production deploys on the
first of every month and then a major release once every few months.
The major release needs to be retrofitted with the changes done in the
smaller release too. Is there an optimum way of going about
implementing this without running into issues like missed code or
overwriting changes?

I will appreciate any help on this. Also, if there are any documents /
papers on this, please forward me the links.

Thanks in advance,

Sandeep