The phrase "several drafts" means that something, like a document or an artwork, has gone through multiple versions or revisions before reaching the final version. Full definition
You've made scientific sense of several years of research data, pulled your results into nifty figures, and gone through several drafts of narrative. (sciencemag.org)
Going through several drafts takes time, but it will increase its chances. (publishingtalk.eu)
I typically write several drafts before posting something controversial. (rachelheldevans.com)