1. A non-transitory computer readable medium storing instructions executable by at least one processor to perform operations, where the instructions provide a message-based interface for exchanging information about material valuation data, the operations comprising: receiving, at first application, via a message-based interface derived from a common business object model, where the common business object model includes business objects having relationships that enable derivation of message-based interfaces and message packages, the message-based interface exposing at least one service as defined in a service registry and from a second application different from the first application, the second application executing in an environment of computer systems providing message-based services, a first message for requesting maintenance of a bundle of material valuation data, the first message including a first message package hierarchically organized in memory, the first message package including: at a first hierarchical level in the first message package, a material valuation data bundle maintain request sync message entity; and at the first hierarchical level in the first message package, a material valuation data bundle maintain request sync package including, at a second hierarchical level in the first message package, a material valuation data bundle maintain request sync entity, wherein the material valuation data bundle maintain request sync entity includes, at a third hierarchical level in the first message package, at least one material valuation data entity from a material valuation data package; processing the first message based on the hierarchical organization of the first message package, where processing the first message includes unpacking the first message package based on the first message package's structure and the first message package's derivation from the common business object model, wherein the particular structure of the first message package is used at least in part to identify the purpose of the first message; and sending a second message to the second application responsive to the first message, where the second message includes a second message package derived from the common business object model to correspond to the semantics of the first message package.