Calculation of reduction on audit time - IAF MD1:2007, IAF MD5:2015 and IAF MD11:2013

Hi, I have a question concerning the calculation of reduction on audit time. In IAF MD1:2007, IAF MD5:2015 and IAF MD11:2013 are the rules described how to handle with the calculation of the reduction. It's stipulated that reduction time is limited to 30% and accordance the maturity of the system, nevertheless, some certification bodies goes up to 50%. Is that feasible?
What are the consequences for the compagny if the certification body grant more then 30% of reduction time ?
If the compagny have a groupcertificate with multiple plants, how to calculate the reduction time ? Allowed to starting from the reduction time defined in IAFMD5:2015 and plus on that grant maximum of 20%.
Note.: which tables are used to define the risks for OHSAS and ISO 5OK?
Thanks in advanced to help clarified this issues.
Gr. Filip

Re: Calculation of reduction on audit time - IAF MD1:2007, IAF MD5:2015 and IAF MD11:

In the case of my own experience, top management used to be able to approve time deduction over 30% but in the past year the practice was stopped, for all standards.

Annex B of IAF MD-5:2015 gives guidance for complexity.

Failure to adhere to these MD-5 criteria would likely result in a nonconformity issued during accrediting body audit. I can't say for sure what the consequences for the client would be.

Is your CB accredited by a body on the IAF Member list?