Business chains increasingly rely on the dynamic integration of business processes of different partners. The interaction constraints that result from the business processes are captured in business protocols. Since the business protocols of each partner support its own way of working, the business protocols can easily mismatch, which hinders organizations from forming a business chain. Such mismatches can be resolved by protocol adaptors. In this paper, we show how protocol adaptors can be used to enable the flexible formation of business chains. For different types of business chains, we present formation cases that describe which partners are responsible for the construction and operation of protocol adaptors. Next, we present for each f...