US Patent 7987187 Quantity offsetting service

Embodiments include a system for providing a set of services that retrieve requested data and calculate a requested value. The data retrieval service may traverse a set of related data structures such as data in a document or in a database to accumulate and return requested data. The data calculation service may determine an appropriate algorithm based on the data being processed and return a value. The data calculation service may call the data retrieval service to obtain the necessary data. These services may be independent services separate from other software applications. These services provide standard data determination and calculation functions across multiple applications and are accessible in a common software layer.