Consistent interface for customer project expense list and deviating tax calculation rule

A non-transitory computer readable medium including program code for providing a message-based interface for exchanging information about cost object expense lists, including accounting notifications, the program code operable when executed by a process to:

• receiving 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 heterogeneous application executing in an environment of computer systems providing message-based services, a first message for providing a notification about expenses arising from and collected during a customer project, including information regarding how to invoice expenses or how expenses have been invoiced to a customer, the first message including a first message package derived from the common business object model, the first message package hierarchically organized in memory based on the common business object model, the first message package including:
• at a first hierarchical level in the first message package, a cost object expense list accounting notification message entity;
• and
• at the first hierarchical level in the first message package, a cost object expense list accounting notification package including, at a second hierarchical level in the first message package, a cost object expense list accounting notification entity, an expense original entry document reference package, and an item package, wherein the cost object expense list accounting notification entity includes, at a third hierarchical level in the first message package, a reconciliation period counter value, an item list complete transmission indicator, an operational document containing business object reference, an operational document reference, an operational document transaction universally unique identifier (UUID), a company identifier (ID), an accounting business transaction date time and a cost object reference, wherein the expense original entry document reference package includes, at the third hierarchical level in the first message package, an expense original entry document reference entity, and wherein the item package includes, at the third hierarchical level of the first message package, at least one item entity, wherein each item entity includes an action code, an operational document item reference, a sales order reference, a cancelled indicator, a not to be invoiced indicator, and an excess indicator, wherein each item package further includes, at a fifth hierarchical level in the first message package, a pricing package, wherein each pricing package includes, at a sixth hierarchical level in the first message package, at least one pricing entity, and wherein each pricing entity includes, at a seventh hierarchical level within the first message package, a calculated amount;
• processing the first message according to 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 heterogeneous application responsive to the first message, where the second message includes a second message package derived from the common business object model to provide consistent semantics with the first message package.

A distributed system operating in a landscape of computer systems providing message-based services defined in a service registry, the system comprising:

• at least one processor operable to execute computer readable instructions embodied on non-transitory media;
• a graphical user interface executable by the at least one processor and comprising computer readable instructions, embedded on non-transitory media, for providing a notification about expenses arising from and collected during a customer project, including information regarding how to invoice expenses or how expenses have been invoiced to a customer, the instructions using a request;
• a first memory storing a user interface controller executable by the at least one processor for processing the request and involving a message including a first message package derived from a common business object model, where the common business object model includes business objects having relationships that enable derivation of message-based service interfaces and message packages, the first message package hierarchically organized, the hierarchical organization of the first message package including:
• at a first hierarchical level in the first message package, a cost object expense list accounting notification message entity;
• and
• at the first hierarchical level in the first message package, a cost object expense list accounting notification package including, at a second hierarchical level in the first message package, a cost object expense list accounting notification entity, an expense original entry document reference package, and an item package, wherein the cost object expense list accounting notification entity includes, at a third hierarchical level in the first message package, a reconciliation period counter value, an item list complete transmission indicator, an operational document containing business object reference, an operational document reference, an operational document transaction universally unique identifier (UUID), a company identifier (ID), an accounting business transaction date time and a cost object reference, wherein the expense original entry document reference package includes, at the third hierarchical level in the first message package, an expense original entry document reference entity, and wherein the item package includes, at the third hierarchical level of the first message package, at least one item entity wherein each item entity includes an action code, an operational document item reference, a sales order reference, a cancelled indicator, a not to be invoiced indicator, and an excess indicator, wherein each item package further includes, at a fifth hierarchical level in the first message package, a pricing package, wherein each pricing package includes, at a sixth hierarchical level in the first message package, at least one pricing entity, and wherein each pricing entity includes, at a seventh hierarchical level within the first message package, a calculated amount;
• and
• a second memory, remote from the graphical user interface, storing a plurality of service interfaces, wherein one of the service interfaces is operable to process the message via the service interface.