UNI 11337-8 is the Italian standard on the requirements for an organisation's BIM management system: how those who design, build or operate assets organise the processes, roles, tools and controls of digital information management. It has replaced UNI/PdR 74, the reference practice against which BIM management systems were certified until now.
Certification is issued by an accredited certification body, after an audit of the documents and of sample projects. Project processes remain those of ISO 19650 and the UNI 11337 series: the management system shows that the organisation applies and controls them. The pre-audit makes sure you do not reach the audit with procedures that are written but not applied.