The TM Forum has published the results of their 2017/18 revenue assurance survey. Their survey team is headed by Rene Felber of Telia, and here is a short video where Rene explains the purpose of the survey.
To be honest, I have not had time to read all the detail of the 49-page report. But this is the fifth edition of the survey since 2012, so anyone familiar with the previous surveys will know what to expect. A quick skim through the pages indicated there were no surprising findings nor significant changes in approach compared to previous years.
You can obtain the survey report from here.