The integrity of data should be the greatest concern for a risk practitioner upon learning of failures in a data migration activity, because it affects the accuracy, completeness, and consistency of the data that are transferred from one system or format to another. Data integrity is a property of data that ensures that the data are valid, reliable, and trustworthy, and that they have not been altered or corrupted by unauthorized or accidental means. Data migration is a process of moving or copying data from one system or format to another, usually as part of a system upgrade, consolidation, or transformation. Data migration can pose risks to the integrity of data, such as data loss, duplication, inconsistency, or corruption, due to factors such as incompatible formats, human errors, technical glitches, or malicious attacks. Therefore, the integrity of data should be the greatest concern, as it impacts the quality and usability of the data, and the performance and functionality of the system. The availability of test data, the cost overruns, and the system performance are all possible concerns for a risk practitioner, but they are not the greatest concern, as they do not directly affect the integrity of data. References = Risk and Information Systems Control Study Manual, Chapter 4, Section 4.3.2, page 158
