Probabilistic method or risk assessment has been introduced to enhance deterministic approach in monitoring power system security. In general, risk assessment monitors power system security quantitatively by measuring the product of probability of disturbance to occur and the impact of such disturbance towards security violation. This research is performed to classify the risk of voltage collapse that would occur due to transmission line outage using risk matrix technique. The underlying principle of risk matrix method is to reflect the changes in risk components in the overall system classification assessment. To evaluate the effectiveness of this method, comparative study between risk matrix and conservative method is conducted. Based on the findings, it is revealed that risk matrix offered more comprehensive and reflective results as compared to conservative approach.