For many organizations, the continuous optimization of their business processes has become a critical success factor. Several related methods exist that enable the step-by-step redesign of business processes. However, these methods are mainly performed manually and require both creativity and business process expertise, which is often hard to combine in practice. To enhance the quality and effectiveness of business process redesign, this paper presents a conceptualization of assisted business process redesign. The aBPR concept guides users in improving business processes based on redesign patterns. Depending on the data at hand, the aBPR concept classifies four types of recommendations that differ in their level of automation. Further, this paper proposes a reference architecture that provides operational support for implementing aBPR tools. The reference architecture has been instantiated as a prototype and evaluated regarding its applicability and usefulness in artificial and naturalistic settings by performing an extensive real-world case study at KUKA and interviewing experts from research and practice.