Collective action is a means to an end and a way of achieving strong WASH systems, at all levels. It is based on the assumption that to achieve positive change in any complex system will require many independent actors and the incentives that drive them to align to produce different and more positive outcomes; in this case more sustainable, better and more universal WASH services. It does however have a more explicit and intentional focus on building coalitions, partnerships or movements that are dedicated to driving long lasting systems change. Such collective action can be established at local, national and global levels and indeed it is a core element of collective action to have “vertical” linkages and flows of interaction and learning between these levels, as well as “horizontal” interactions. Collective action involves different stakeholders, at times with differing opinions and perspectives, interacting and collaborating to address and solve common or shared challenges. Collective action should include all stakeholders or at least account for their perspective/position and usually includes a platform or mechanism for coordination and learning, sometimes referred to as a Learning Alliance supported by a hub or a backbone organization. Collective Impact is a branded version of collective action, which was developed by the US-based group FSG.