Would you recommend the use of HR Constants? Why?

Yes if internal recruitment team is not there.

Yes, because every position and work require the best, right person for right job. That's why it is recommended.

HR Consultants can prove to be very useful for short-term and highly specialized assignments which cannot be executed using the company's internal talent.

Yes, but only for strategic HR decisions not internally available. 

Yes, but only if you are very clear about what you need them for and what the costs and benefits are. 

In general, HR consultants should be hired only for a specific project which is outwith the usual course of operations for the HR department, if you have such a thing.  Examples are when there is a major change in the size of the workforce (e.g. opening or closing a factory) or when there is a complete overhaul of the salary and benefits system in the company.

Thanks for invitation,

Yes, as long as "the job distributions" are remain the same.

Thank you for the invitation.

Of course, because the fundamentals of what science has been proven correct and turned into a static thing after that was the theory of the day.

Yes, I would recommend it.

yes, because there are some tasks that require special expertise and does not require full time employment

yes ill recommend a HR... thanx for the invite

Thanks for the invitation

Yes, specialties  important in HR