How do we sustain the use of agile methodologies both in our project teams and in our organisations? How do we know we have improved our project performance by using agile methods? How can we assimilate agile methods more deeply into our organisations? These questions are the focus of this workshop on agile sustainability. Much of our time is spent understanding how to implement agile methodologies but less is spent on understanding how we can sustain these methodologies and the ramifications if we do not sustain them. Agile methodologies have well passed the phases of adoption in many organisations. Yet the ultimate success of an agile methodology depends on the sustained use of the method both on the project team and in the organisation. Within an organisation, the greater the amount of project teams using agile methods and the deeper the use of agile practices are assimilated into that organisation, the greater the likelihood of specific improvements in agile systems development outcomes. However, what facilitates the early stages of agile assimilation in an organisation is different to what facilitates the later stages of the assimilation. Therefore, this workshop and its participants will discuss the key factors that either facilitate or prevent the sustainability of agile methods in an organization. We will discuss how to achieve significant improvements in agile systems development projects and provide an overview of mechanisms that can be used to track improvements during organizational assimilation of agile methods. Participants should have at least two years working experience in agile projects and include a wide range of roles such as manager, scrum master, business analyst, product owner, testers and developers.