Is Actuarial Valuation is Mandatory or Advisory as per AS 15?

Hi, whether the Actuarial Valuation as per AS 15 is Mandatory or Advisory? The language in Paragraph 49 of the said AS seems to be advisory, but, some of the professionals are saying it is mandatory. So, I would like to know the opinion of the experts here. I am placing the extract of the paragraph below:

"While the Standard requires that it is the responsibility of the reporting enterprise to measure the obligations under the defined benefit plans, it is recognised that for doing so the enterprise would normally use the services of a qualified actuary"

Thanks in advance.