Due to the increasing demand being made upon distributed information processing, local area networks (LANs) have captured the interest of a host of people across the world. LANs are expected to become a major communication and cooperation tool for information processing systems in factories and offices of the near future. They are intended to have wide applicability in many environments and will allow to bind together various components of automation systems, connect many different resources and will carry various different types of information among them. Some of the claimed benefits are economic aspects, good response time, great througput, enhanced resource utilization, system expandability etc. A LAN system designer or developer who invests in LAN architecture, implementation or realization without first addressing questions on capabilities qualitative and quantitative aspects of alternative concepts in terms of performance analysis, prediction and evaluation as well as system overhead analysis studies, may be in for an expensive lession. To address these issues, one must be capable of empirically evaluating an entire system, prior to prototyping and testing the system. Computersimulation can provide powerful tools for that purpose. In this paper I present such a tool: LAN-PEP.