Before Enterprise resource planning

Prior to the concept of ERP systems, departments within an organization (for example, the human resources (HR)) department, the payroll department, and the financial department) would have their own computer systems. The HR computer system (often called HRMS or HRIS) would typically contain information on the department, reporting structure, and personal details of employees. The payroll department would typically calculate and store paycheck information. The financial department would typically store financial transactions for the organization. Each system would have to rely on a set of common data to communicate with each other. For the HRIS to send salary information to the payroll system, an employee number would need to be assigned and remain static between the two systems to accurately identify an employee. The financial system was not interested in the employee-level data, but only in the payouts made by the payroll systems, such as the tax payments to various authorities, payments for employee benefits to providers, and so on. This provided complications. For instance, a person could not be paid in the payroll system without an employee number.

http://en.wikipedia.org/wiki/Enterprise_Resource_Planning