Agile methodologies (AM), which emphasize iterative and incremental development with just-in-time processes and documentation, have been adopted by an increasing number of organisations. Despite this progress there is lack of clarity on their effective use after initial adoption. While there is much research on the use of various agile methods and practices, there is very limited understanding on the critical factors that impact their continued and effective usage. To address this gap, an integrated model called the Agile Usage Model (AUM) was developed, by coalescing insights from organisational level Information Systems implementation, traditional innovation diffusion models, and post-adoptive agile usage. The objective of this study is to use multiple data collection methods to further evaluate and refine the AUM. The final refined conceptual model of Agile Usage is presented along with implications for research and practice.