Wont this make employees feel that they'd rather not have coffee?
Please do let us know the honest opinion of employees on this system. To my observation - it is such kind of an act that results in the total failure of employee motivation.
I understand when people say that the management is tough on such decisions, but for once talk back and ask them "What difference is it going to make by stopping or highly monitoring them on coffee consumption except for lowering their motivation?"
Monitor on performance, guide employee if their attitude is failing. On such kind of allowances we should not set a limit or rather a "monitoring system".
Majority of us are in the opinion that the HR should not encourage on going ahead with reducing consumtion of tea/coffee. Use the HR position to the benefit of both employees and Employer. Use the power of this position and let the employers know that it makes no sense at the end of the day! (The power here is the ability to present the employees to the Management) - In a diplomatic, yet a strong message conveyed manner.