This book conceptualises and develops crowdsourcing as an organisational business process. It argues that although for many organisations crowdsourcing still implies an immature one-off endeavour, when developed to a more repeatable business process it can harness innovation and agility. The book offers a process model to guide organisations towards the establishment of business process crowdsourcing (BPC), and empirically showcases and evaluates the model using two current major crowdsourcing projects. In order to consolidate the domain knowledge, the BPC model is turned into a heavyweight ontology capturing the concepts, hierarchical relationships and decision-making relationships necessary to establish crowdsourcing as a business process in an organisation. Lastly, based on the ontology it presents a decision tool that provides advice on making informed decisions about the performance of business process crowdsourcing activities.