RCR RMR is derived from the RMR system by reducing two parameters (i.e. ratings for the crushing strength of intact rock material and the adjustment of joint orientation) out of six parameters in the original RMR system. Each of these systems has some shortcomings, but the combined assessment is more effective (Palmstrom and Broch, 2006). This classification system acts as a first hand tool for site engineering geologist for primary evaluation of rock mass condition and the required support system. The results of calculated rock mass classification values are summarized in Table 4.