This document provides an introduction to modeling customer arrival and service processes at a bank. It defines key elements of a model including entities (customers), arrivals, locations (waiting area and teller area), resources (tellers), and paths. It also demonstrates how to map the bank process, including customers arriving and waiting in line, moving to a teller for service, and then departing once served. The modeling approach uses outline process maps with standard symbols to represent the system and build the logic for simulating customer flows.