Young male technician testing a printing machine to determine the cause of failure, to be documented by a CMMS cause code.

This article is part of a series of articles on the topic of equipment failure tracking. Read our other articles on this topic:

What are Cause Codes?

The first article of this series, What is a Failure Code?, establishes that failures codes are a way to document the state of a failed asset, as determined by an observer. Because they only capture the problem with an asset, failure codes alone do not paint the whole picture of a failure event. Cause codes help to fill in this missing information.

A cause code, sometimes called a reason code, is a value used to uniquely identify a type of failure cause and is often found in a computerized maintenance management system (CMMS) or other asset management system. Like failure codes, cause codes are a combination of an alphanumeric code and a description. Cause codes are used to record the underlying reason for the problem identified by the failure code.

Where are Cause Codes Used?

Cause codes are used in maintenance management software along with failure codes for asset failure tracking. They are applied to work orders to identify why a problem occurred. In most cases, technicians cannot identify the reason for asset failure without investigating the issue and testing solutions to see if a repair corrected the issue. Therefore, cause codes are commonly entered after work has been completed, though they are sometimes entered during troubleshooting.

Why Use Cause Codes?

There are many reasons organizations use CMMS cause codes.

Improved Maintenance Effectiveness

A description of a failure is often too simplistic to be useful. Without understanding the root cause of an asset failure, technicians are only treating the symptoms of failure and not preventing it from occurring in the future. Cause tracking provides a starting point for failure analysis and the creation of maintenance tasks that reduce the likelihood of failure.

Improved Downtime Tracking

Rather than simply documenting that downtime occurred without explanation, cause codes connect downtime events with a reason for failure. As this information is gathered over time, organizations can drill into the data to identify patterns in downtime and develop plans to reduce it. Recurring issues may warrant more frequent preventive maintenance or identify additional training needs for certain maintenance tasks. Without identifying the true cause of the downtime, it is likely to happen again.

Improved Troubleshooting

When troubleshooting, a technician may first use a CMMS to find historical work orders whose failure code matches what they have observed or what has been reported. Next, the technician may look at the paired cause code to understand what has caused the failure in the past. This failure code-cause code pair provides better direction for troubleshooting, allowing technicians to start investigating the most likely causes first.

Additionally, the use of cause codes refocuses the efforts of the maintenance team to investigate reasons for failure. Otherwise, technicians might simply make repairs and move on, thereby increasing the likelihood the failure will reoccur.

Implementation of Asset Lifecycle Management Practices

Both basic and advanced methods of asset life cycle management rely on collecting information about failures and their causes in order to reduce downtime, extend asset life, and optimize lifetime asset maintenance expenses. As asset lifecycle management strategies become more advanced, cause tracking becomes more important.

For example, to reduce downtime, organizations perform root cause analysis (RCA) to help maintenance staffs backtrack through the steps leading up to failure in order to understand the conditions that prompted it. Building off RCA, failure modes and effects analysis (FMEA) identifies an asset’s failure modes and their associated risks in order to extend asset life. Going a step further, organizations that practice reliability-centered maintenance (RCM) develop maintenance plans to prevent failures, based on their cause, in the most cost effective manner.

CMMS Cause Code Construction

The information required to construct cause codes comes from high-level maintenance employees and tradesmen, maintenance history, and practical experience with an asset. Employees who have expertise in electrical, mechanical, and pneumatic systems have an in-depth understanding of probable issues that can occur. Maintenance history, stored in a CMMS, provides a database of failure and repair data from which to generate cause codes. In some organizations, the maintenance and engineering teams work together to devise the cause code library.

Cause Code Design

Like failure codes, cause codes are typically unique to each organization. First-time users may favor broad, high-level cause codes that represent the general system causing issues. Not only are broader cause codes easier to construct, but they make it easier to start process improvement as well.

Granular, asset-specific cause codes are better suited for experienced maintenance teams who operate under an established cause tracking system. If making cause codes too specific, maintenance managers may also have trouble identifying cause trends. Also, inexperienced technicians are likely to erroneously assign failure causes and compromise failure data. However, if the CMMS supports it, specific cause codes might be nested under more general cause codes, providing both novice and veteran workers with the ability to document causes.

Regardless of which approach is taken, it is important to keep in mind that tracking causes is not an ending point – it is a starting point for deeper failure analysis. Therefore, the simplicity or complexity of the cause code library should match the organization’s requirements.

Cause Code List Example

Below is an example of a generic cause code list. Note that this list is not exhaustive of all causes of equipment failures.

Cause Code Cause Code Description
AF Pneumatic failure
EF Electrical failure
HF Hydraulic failure
MF Mechanical failure
PM Inconsistent preventive maintenance
SF Start-up failure

CMMS Cause Code Best Practices

The goal of developing cause codes is for CMMS users to be able to track why asset failures occurred on work orders. Keep the following best practices in mind when constructing cause codes:

  • Consider Team Experience: Technicians experienced in a particular trade or craft will be able to more easily identify the probable cause of an asset failure. Making cause codes too complex will result in less-experienced technicians picking the wrong codes. Start with a simple cause code library – the list can become more granular as the team grows into the use of the system.
  • Keep the Cause Code List Size Manageable: There is a delicate balance between too many and too few cause codes. List size will partially depend on team experience. However, also consider the ease of analyzing the data. Starting with broad cause codes allows organizations to dig deeper into issues. Starting with too many cause codes that are too specific can make it difficult to “see the forest through the trees” and understand the larger issues at hand.
  • Make Cause Codes Foolproof: Cause codes should be constructed in such a way that they are easy to memorize, hard to misunderstand, not easily confused with one another, and have specific meanings that do not overlap with one another. Doing so will maximize the value of failure cause tracking while limiting mistakes or faulty data.
  • Hold Team Accountable for Use: Cause codes will only be effective if used consistently and correctly. A CMMS allows you to verify that cause codes are used properly, and becomes a reference point for identifying and correcting mistakes.
  • Review and Update the Cause Code List: Cause code lists are not set in stone. During analysis, it is possible that causes are being miscategorized or that additional cause codes are needed. Periodically review the cause code library and update when appropriate.


Cause tracking makes maintenance more effective by tracking the reasons why assets fail. Based on the root causes of failure, organizations can implement highly targeted maintenance tasks that treat causes, not symptoms. FTMaintenance Select is a CMMS that allows you to easily plan, schedule, and document maintenance activities on critical equipment and facility assets. Request a demo today to learn more about FTMaintenance Select.

This article is part of a series of articles on the topic of equipment failure tracking. Read our other articles on this topic:

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