# Introduction

Sub-models provide an excellent mechanism for managing diagram complexity. Sub-models enable you to "drill down" into the various stages of a process, to represent sub-processes with a greater degree of detail. The space within which each Sub-model is represented can be selectively shown on the diagram, or hidden from view. As a result, you can control the pace at which diagram detail is revealed. By managing detail, Sub-models can keep you (as well as users of your models) in control of the complexity.

This Chapter is a practical guide to the creation and use of Sub-models. Throughout the Chapter, you'll find hints and tips which will help you to make most effective use of the software's Sub-model capabilities.