The communication skills of testers is least likely to be improved using the TMMi model. While TMMi focuses on improving structured test processes, including static testing (such as reviews), unit testing, integration testing, and the management of test environments, it does not explicitly address the soft skills, such as communication, that testers may need to effectively interact with stakeholders. These skills are typically developed through other training or team-building initiatives, not through process improvements outlined by TMMi.
Reference:
"The TMMi model focuses on improving testing processes and management but does not specifically target the development of communication skills" .