The current business environment has become more risky and variable. In particular, the recent terrorist attacks against western economies have revealed the vulnerability of global supply chains. These events showed that companies that move cargo internationally are subjected to a broader spectrum of risks, for which they might not be yet prepared. The perception of a higher level of security risks has motivated a wide variety of efforts from the academic, public and private sectors to increase global supply chain security. First, governments, border agencies and international organizations are designing and promoting new security initiatives and regulations to force companies to take more responsibility for the security of their supply chains. Second, academics have started to apply traditional concepts of risk and security management to the supply chain context, leading to the theory of supply chain security management (SCSM). Third, companies are following the new mandatory security regulations. However, most of them are still waiting before implementing those initiatives which are not yet mandatory. At the moment, each of these parties is approaching this problem from different a perspective. However, they all face one main common challenge: Increasing security without affecting supply chain performance or creating new trade barriers. The management of security in a supply chain environment has been usually associated with the implementation of rules and activities that are obstacles for the efficient flow of goods, non-value adding operations or cost generators. It is therefore necessary for these parties, to develop security initiatives which enhance security without affecting supply chain performance or jeopardizing trade. This study builds on the theory of SCSM which is still in its infancy. The literature review shows that some of the most relevant gaps are: i) the disconnection between the governments and border agencies' security initiatives and the theory developed by academics, ii) the non-inclusion of a systematic, holistic and process perspective in the design of SCSM initiatives, and iii) the lack of adequate management tools for companies to implement and maintain the new SCSM initiatives. Based on these literature gaps and the challenges imposed by the new supply chain security risk context, the main research question of this study is: How companies and governments can develop effective (capable of reducing the probability of disruptions occurrence) and resilient ( preparing the supply chain to recover from disruptions) SCSM systems? The main goal of the study is to develop a SCSM model which can help companies and governments to make use of the most relevant lessons from the existing academic theories and the new security initiatives, by integrating them in one practical comprehensive management tool. The research study investigates the supply chain security management by companies with large experience in managing high-risk areas and products. Initially, a survey is conducted to study how some of these companies have increased their security level by implementing a voluntary security program. The analysis of this data enables the identification of some of the factors which can positively impact the success of these programs and confirms the systemic nature of supply chain security management programs. Following these results, supply chain security systems are studied from a more holistic perspective by carrying out two in-depth case studies. The analysis and comparison of these case studies allow the identification of the most relevant challenges that these companies face to manage their supply chain security. Furthermore, they show that the traditional methods of corporate security management present several obstacles to deal with these challenges. The lessons and insights obtained through the analysis of the empirical data, together with the SCSM best practices identified in the literature, are integrated into the proposed "Supply Chain Security Management Model". This model provides a concrete framework to help practitioners adding the process dimension to the management of security. The framework also allows a better understanding and managing of the interactions between the supply chain and the security systems. To complete this research study, the model is validated by applying it to the two case study companies. The results of this initial exercise show that the proposed SCSM model constitutes an innovative management tool for the evaluation of SCSM systems, which drives the attention to critical points that were neglected in the past. This practical application exemplifies how the model can be used to collect and represent in a comprehensive way the security related information that is usually spread amongst different company functions and business partners. The main advantage of such representation is that it allows for a quick identification of the areas with potential for improvement.