# Downtime Tracking

> Source: https://netray.co/glossary/downtime-tracking
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: Glossary

## Short answer

Downtime tracking is the systematic recording of when a machine or line stops, for how long and for what reason, so that planned and unplanned stoppages can be measured, categorized and reduced.

## Aliases

- machine downtime tracking
- downtime reason codes
- stoppage tracking

## Category

manufacturing

## Full Definition

A stop is recorded with a start time, end time, machine and a reason code. Machine signals (run, idle, fault) give accurate timestamps. Operators or technicians add the reason, such as no material, changeover, tool break, mechanical failure or waiting on quality. A short, well-designed list of reason codes is critical: dozens of codes produce an unused list, and the code Other becomes the biggest bucket.

Downtime is the availability component of OEE. Analyzing it with a Pareto chart shows the few causes responsible for most lost hours. It also splits planned stops (changeovers, scheduled maintenance, breaks) from unplanned ones, which need different responses: SMED for changeovers, maintenance strategy for breakdowns, material staging for starvation.

ERP-based data collection can capture indirect labor or machine down transactions, but dense machine data usually comes from an MES, a machine monitoring system using MTConnect or OPC UA, or PLC counters. The data is also used by maintenance modules to compute MTBF and MTTR and trigger work orders.

## Why It Matters

- You cannot reduce losses you do not measure, and manual estimates usually understate them.
- Reason-coded stops direct improvement effort to the biggest cause rather than the loudest complaint.
- It supplies the availability figure for OEE and the failure data for MTBF and MTTR.
- It supports capacity decisions: spare hours may be hiding in downtime, avoiding premature machine purchases.

## In Practice

A machining cell reports 62 percent availability. Reason-coded data over four weeks shows 35 percent of lost time is waiting for material, 30 percent is changeover, 20 percent is tool breakage and the rest is a mix. The team stages material at the cell and standardizes tool presets, raising availability toward the high 70s without any new equipment purchase.

## Faq

### What are common downtime reason codes?

**Answer:** Changeover, no material, no operator, tooling, mechanical or electrical breakdown, waiting for quality, planned maintenance and break. Keep the list short and review it regularly.

### Can downtime be tracked without sensors?

**Answer:** Yes, with operator entries on a terminal, but accuracy depends on discipline. Machine signals give precise timing; operators add the reason.

### How does it relate to OEE?

**Answer:** Downtime determines availability, one of the three OEE factors alongside performance and quality.

## Search terms

downtime tracking, machine downtime, downtime reason codes, unplanned downtime, machine monitoring, availability loss, downtime pareto

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