We present a case-based planning (CBP) model. The important component in the memory of the system is the collection of different structures of created plans. A structure is made up of created plans arranged in a hierarchical fashion, and corresponds to a class of plans. Retrieving, modification, and storing mechanisms play a key role in plan construction. In contrast with most existing CBP systems, these mechanisms are distributed over plan operators. A plan is created in a hierarchical fashion by activating the suitable structure and performing step wise retrieving, modification, and storing operations on it. The system learns new plans from experience and has been implemented in the domain of cooking vegetables.