This thesis focuses on the transition from multichannel to omnichannel retailing. To provide insight into this, the current challenges and related indicators are identified by means of a multiple case study. In addition, a theoretical framework for the omnichannel retailing concept is designed. On the one hand, this will help to increase the understanding of omnichannel retailing and, on the other hand, it will provide insight into where retailers currently find themselves in this transition and what challenges this involves.