  Context: Existing knowledge in agile software development suggests that
individual competency (e.g. skills) is a critical success factor for agile
projects. While assuming that technical skills are important for every kind of
software development project, many researchers suggest that non-technical
individual skills are especially important in agile software development.
Objective: In this paper, we investigate whether non-technical individual
skills can predict the use of agile practices. Method: Through creating a set
of multiple linear regression models using a total of 113 participants from
agile teams in six software development organizations from The Netherlands and
Brazil, we analyzed the predictive power of non-technical individual skills in
relation to agile practices. Results: The results show that there is
surprisingly low power in using non-technical individual skills to predict
(i.e. explain variance in) the mature use of agile practices in software
development. Conclusions: Therefore, we conclude that looking at non-technical
individual skills is not the optimal level of analysis when trying to
understand, and explain, the mature use of agile practices in the software
development context. We argue that it is more important to focus on the
non-technical skills as a team-level capacity instead of assuring that all
individuals possess such skills when understanding the use of the agile
practices.
