It is commonly accepted that an individual’s beliefs and actions are based on their assessment and perceptions of the world they inhabit. In order to determine what practices an individual is likely to follow at any given time, it is necessary to understand the individual's behavioural intention in a given circumstance. From an Information Technology perspective, software development professional’s belief systems are potentially the basis for the adoption and implementation of new and innovative work practices and processes. In this paper we explore the belief systems of software development professionals to understand the beliefs underlying intention and practice, and seek answers about how they adopt or reject new and innovative software development processes and practices. The results point out a strong influence of past experiences, personality types and repeated behaviour on current software development processes and practices in industrial settings.