"The Australian Department of Defence (ADoD) is undergoing a fundamental restructure, one aspect of which aims to ensure that it has a robust military capability acquisition process. A key component of this restructuring is the establishment of an internal contestability capability to review ADoD's requirements, acquisition, and budget decisions internally before they are passed to other elements in the government. The role of this contestability function is to help ensure that the requirements and the resultant capabilities delivered to the Australian Defence Force are aligned with articulated strategy and available resources. To help develop this capability, the ADoD engaged the RAND Corporation to identify and review international contestability practices.This report details RAND's findings. It describes key contestability functions and the primary aspects of those functions, as described in the literature. The report also provides the results of case studies of contestability functions in a variety of public and private organisations. RAND found that different organisations take a wide variety of approaches to implementing and conducting contestability functions. Still, there was a pervasive understanding that contestability could be linked to better outcomes and that a structured review of decisions could help reduce or avoid problems"--Publisher's description.