1. A method in a computer system for managing employee data for an enterprise, comprising: defining an employment data model including three tiers, the tiers including a relationship tier for storing work relationship information for each employee of the enterprise, a terms tier for storing employment terms information relating to any relationship in the relationship tier, and an assignment tier for storing assignment information for any terms in the terms tier; storing employee data for an employee of the enterprise in a data repository according to the employment data model; and retrieving employee data from the data repository and presenting the retrieved employee data in response to a request, wherein storing the employee data includes determining from the employee data each relationship that the employee has with the enterprise, determining each set of terms for each relationship of the employee, and determining each set of assignments for each set of terms for the employee, and storing the employee data according to the three-tier employment data model, and wherein retrieving employee data includes determining from the request which relationship, terms, and assignment information for the employee is to be presented in response to the request.