Mumbai-based Tata Consultancy Services, India's largest IT services provider, today said around 500 (around 0.5% of its total employee strength) of its staff had resigned due to poor performance.The move follows the cut that the company recently effected on a portion of the variable pay linked to the employees performance, reducing the salary by about 1.5% for the January-March 2008 quarter."Our company has a biannual appraisal system - one between June and July, and the other in January-February -- where we rate employees on a scale of 1-5 (5 being the highest). Those employees who score a low figure of 2, for instance, are asked to either repeat their training programme or are sent for counselling - depending on whether they are freshers or middle management executives. Those who cannot meet the performance requirements of our company are asked to look for another job," a TCS spokesperson told this paper.Analysts, however, attribute the move to IT firms getting tough on the employee productivity front due to the effects of a rising rupee against the dollar.Last year too, around 500 people met a similar fate since they could not meet the performance rating numbers, the spokesperson added.In the third quarter ended December 31, 2007, TCS added 4,037 net staff taking its total headcount to 108,229, up from 83,500 a year ago.