1 Fault attribution refers to the assignment of responsibility for problems with the Tube. Early data collected by LUL between January 2003 and September 2003 for the JNP lines, and April 2003 to September 2003 for the SSL and BCV lines, shows that in a the vast majority of cases -98.5 per cent - attribution is ascribed without dispute to either LUL, one of the Infracos, or some combination thereof without dispute. In approximately 1.5 per cent of cases however - typically items with significant financial impact -there is disagreement over who is responsible and attribution negotiations are required (see Figure 12 for more on the generic process of attributing fault).
2 For example, the operation of an emergency alarm on a train by a passenger is generally a LUL responsibility and it therefore takes the attribution. On the other hand, a defective asset or asset failure is an Infraco responsibility and it takes the attribution.