Recent advancements in technology have enabled businesses to automate their structured business processes, thus requiring minimum intervention from end-users. This has shifted attention towards less structured processes, which are ad-hoc, often undocumented and demand frequent human decision-making. These processes are referred to as Unstructured Business Processes (UBP). Currently available tools and technologies are mainly focused on structured processes and therefore not optimally suited for management of UBP. With a representative example, we performed an experiment to compare and assess the ability of existing process support paradigms, i.e. Business Process Management and Case Management, to manage UBP. Moreover, we also investigated the limitations of Business Process Model and Notation (BPMN) and Case Management Model and Notation (CMMN) for modeling UBP. Based on our findings, a set of requirements are derived that are needed for optimally managing and modeling UBP. These requirements allow to express end-to-end business processes while providing flexibility for run-time changes. The requirements are also demonstrated with a possible extension of BPMN.