# System Overview

URL: https://irs.systems/en/docs/ltt/documentation/ltt-gui-manual/gettingstarted/system-overview

A **life time tester** (LTT) is an electric control cabinet, whose purpose is to perform **long term electrical tests** on various electrical devices (so called *devices under test*, or short DUT) under certain **environmental conditions** (temperature, humidity, etc.). One can say, it simulates the aging process or lifetime of an electrical device.

The **IRS LTT software**, which comes with every **IRS life time tester** is composed of several parts.

![System Overview](/docs/assets/ltt/assets/system-overview.png)

This is the documentation of the IRS LTT software, including the graphical user interface (GUI), the TestStand sub system and all other related components.