Trajectory correction studies for the CNGS proton beam line

The aim of this study was to chek the performance of the previously proposed trajectory correction scheme for the CNGS proton beam line. We would ike to answer the following questions: Is this proposed scheme sufficient? can we save some correctors or monitors? What happens if something goes wrong? (i.e. faulty correcors or monitors)? We also attempt to identify possible critical scenarios which may not be visible in a purely statistical analysis. this is based on common sense and largely on the experience from SPS and LEP trajectory and orbit correction problems.