Information security plays a significant role in recent information society. Increasing number and impact of cyber attacks on information assets have resulted the increasing awareness among managers that attack on information is actually attack on organization itself. Unfortunately, particular model for information security evaluation for management levels is still not well defined. In this study, decision analysis based on Ternary Analytic Hierarchy Process (T-AHP) is proposed as a novel model to aid managers who responsible in making strategic evaluation related to information security issues. In addition, sensitivity analysis is applied to extend our analysis by using several "what-if" scenarios in order to measure the consistency of the final evaluation. Finally, we conclude that the final evaluation made by managers has a significant consistency shown by sensitivity analysis results.