The advances in Information System (IS) technology in recent years have allowed manufacturing enterprises to use and apply increasingly sophisticated computer-based systems to run their business and to achieve a competitive advantage. However, these systems mostly exist in isolation with minimal (and expensive) integration. Of late, primarily due to emergent competitive global enterprises and markets, the need to be able to integrate the global enterprise has become more urgent. There are many dimensions to the integration problem that relate to IS: integration across geographically distributed enterprises and offices of an enterprise, integration with suppliers and customers, integration of various domains of activities, integration of different tools, collaborative design, etc. In this paper we will identify the different layers and dimensions of the integration problem, the issues and the challenges involved. We will use Saturn Site Production Flow (SSPF), which is a system developed using Model-Integrated Computing approach, as an example of a global application. Then we will examine the issues that arise when a number of different tools and applications have to be integrated in the IS for a large scale and distributed enterprise.