Remedial checks operation techniques can be used to raise the flexibility, to maximize the integration of new generators and to reduce the overall cost. As far as the uncertainties considered, the transmission network should be flexible and economically vigorous. The efficient levels of investment in network reinforcement can be determined by the growth in application of corrective actions to modify the network usage will require a probabilistic treatment of network. A new algorithm is proposed within the developed benders decomposition based investment model which can identify outages and filter out those outages which do not contribute to finding the optimum operating solution. A novel filtering technique is use for efficient elimination of redundant outages , presented and successfully tested. The same technique is used for selecting relevant contingencies.. In numerical examples we compare efficiency of network reinforcement propositions under both deterministic and probabilistic frameworks, while optimizing available preventive and corrective control actions, and in particular focusing on the application of generation reserve in combination with special protection schemes (SPS) for network congestion management purposes. We spotlight the deficiency of the deterministic approach with respect to its inherent inability to maximize correctly the portfolio of pre-fault post-fault actions since the impact of right actions (in the form of SPS, demand response) and occurrence of "non-credible" events require explicit consideration of the feasibility of various outages
