However, at an individual level, to calculate gratuity that valuation might not be required. But for reporting purposes while assessing gratuity for the whole employees, it is required.
For example, formula= last drawn basic pay*no of year’s of service * 15/26 (for twenty years service). Not all the employees have the same service nor they receive the gratuity in the same year. So, out of ten employees, five will receive the gratuity, then actuarial method of assessing the demographic risk factors should be like what is the mortality, disability and attrition rates will be taken into consideration. If only two out of the five will pass this criteria, then, measure and recognise gratuity for only two employees. Once you have established that its for 2 employees only that you have an obligation to pay 20,000₹, then discount it every year to present it in the financial statements. You will also use medical costs and their pay escalations into consideration while calculating the exact amounts. https://cleartax.in/s/ind-as-19#PEB5