1. A method comprising: receiving at a service provider first mapping information at a first time, the first mapping information identifying a correspondence between a first variable included at a first document providing access to information associated with a first software application program and a second variable included at a second document associated with a second software application, the first document and the second document provided by a first customer of the service provider and included at a first system integration application program providing an interface for communicating information between the first software application and the second software application; identifying a first data manipulation operation, the operation to generate a value of the second variable based on a value of the first variable; storing the first mapping information and the first data manipulation operation at a database; receiving a request from a second customer of the service provider at a second time, the request to identify a correspondence between variables included at a third document and variables included at a fourth document, the third document and the fourth document provided by the second customer; determining, by the service provider using a computer, a correspondence between a third variable included at the third document and a fourth variable included at the fourth document based on the first mapping information and based on the first data manipulation operation; and providing, by the service provider, a second system integration application program based on the determining, the system integration application program to provide an interface for communicating information between a software application associated with the third document and a software application associated with the fourth document.