To improve upon existing ERP and other business logic handling system implementations, the claimed system and method provides direct customer access to functionality and data available in a merchant's business logic handling system. The claimed method and system includes installing functions of the business logic handling system at a portable computing device provided by the merchant or owned by a customer, and downloading data corresponding to functions installed at the portable computing device. The customer inputs requests to perform functions of the business logic handling system, and the functions are performed at the portable computing device and/or a system server, and the output of the function is displayed to the custom at the device.