# Introduction

The cycle-time functionality enables you to generate and collect a variety of useful metrics regarding the amount of time that material spends "in process," as it moves through a conserved flow chain. Such metrics can be valuable in a variety of modeling contexts. In particular, cycle-time metrics can be of value when you are engaged in a process re-engineering or process improvement effort. The clear, unambiguous cycle-time metrics provided by the software can help you, both in diagnosing process problems, and in testing and evaluating proposed alternatives.

This Chapter documents the cycle-time functionality. It is divided into three parts. First, the Chapter provides an overview of the cycle-time concepts incorporated into the software. Second, the Chapter walks you through a simple process for putting cycle-time into a model. In so doing, the second section provides an overview of the Builtin cycle-time functions. Finally, the Chapter details the "rules" of cycle-time for a main chain with multiple flows and for a Sub-model, and briefly discusses the changes in internal calculations which are brought about when cycle-time is brought into play.

Each cycle-time Builtin function is documented extensively in the Builtins Chapter of this documentation.