Mr Amar,
Thanks for your question. It mus be known to every HR person. It will increase your Business Accumanship. The HR cost is varying from 2.5% to 13-14% and depend upon the size and volume, class of Business, Product and service, Technology and Level of automisation, modernisation & digitalization etc.
Fundamentally, HR is a support activity and give support to Business by providing skill sets/ competencies across the organisation at all hierarchy levels, work-culture/ work environment, higher employees Engagement, boundary management and Image building of the Organisation.
In view of the above, HR person must know all strategic Planing and revenue ratios, such as fixed cost, Variable cost, market share of the Product/service, HR cost, Consumtion Ratios( Raw material, Energy- Power and Steem), packing matirials ratio, Marketing/ Sales ratios, product/ service mix ratio and Administrative cost ratio etc and their monthly variation ratios from the Budgeted ratios. The HR person must know EBIDTA, PBDT( Proft Before Taxes) and Tax ratio etc too.
Apart from it, He must know the ratios of his department like Employees Engagement ratio, employees turn-over ratio, training cost ratio, departmentwise and levelwise employees cost ratio, Absentee ratio and direct and indirect cost ratios.
I think , now you will have more clarity on your quarry. Please feel free to write any quarry/ question/ thought for discussions.
Thanks