This paper presents a microcomputer-based simulation model of a job-shop type flexible manufacturing system. The model is written in SIMAN and interfaced with C routines in order to create a combined process/discrete-event modeling environment. One of the objectives of this study is to discuss how this environment can be used to schedule orders. The other is to present the results of a comparative simulation study on flexible and prefixed routing of parts in an FMS which is subject to unexpected machine breakdowns. (C) 1997 Elsevier Science Ltd.