---
title: The Cost of Obsolete Automation
slug: cost-of-obsolete-automation
url: /topics/guides/cost-of-obsolete-automation/index.md
publishedAt: "2026-10-14T19:22:26"
updatedAt: "2026-10-14T20:08:55"
excerpt: "By the editors at Reliable. Last updated October 14, 2026. The short version: Obsolete automation shows up in public data as three kinds of numbers: what it costs to keep old systems running, what it costs to resolve one obsolete part, and how much of the installed base is past vendor support. GAO reported in […]"
authors:
  - Reliable Media
---

# The Cost of Obsolete Automation

By [Reliable Media](/authors/reliable-media/index.md)

*By the editors at Reliable. Last updated October 14, 2026.*

**The short version:** Obsolete automation shows up in public data as three kinds of numbers: what it costs to keep old systems running, what it costs to resolve one obsolete part, and how much of the installed base is past vendor support.

GAO reported in July 2025 that 11 critical federal legacy systems, 23 to 60 years old, cost about $754 million a year to operate and maintain. One of them, an Interior Department system that supports dams and power plants, costs $2.3 million a year and runs entirely on hardware and software the vendors no longer support.

The Department of Defense prices obsolescence by the fix. Its published averages run from $1,165 for an approved alternate part to $11.65 million for a complex redesign or system replacement, in FY2021 dollars.

The $65 billion figure that automation vendors repeat is an ARC Advisory Group estimate of worldwide installed value. It first appeared in print in 2003 and has been restated since without a method or an update. The figures in this guide each measure something different, and they cannot be added into one cost.

## How We Evaluated

Independent editorial analysis based on publicly available government data, peer-reviewed research, and the original pages behind widely quoted benchmarks.

Reliable Magazine does not sell control systems, migration services, or consulting and has no commercial interest in routing readers toward any particular vendor. Reliable does not accept payment for rankings. Vendors may sponsor enhanced listings with additional detail, but editorial rankings are independent. [Read our editorial policy](https://reliamag.com/editorial-policy).

We sorted every figure into three tiers and kept the tiers apart:

* Government sources: the Government Accountability Office, the Defense Standardization Program Office, the Commerce Department's Bureau of Industry and Security, and the National Institute of Standards and Technology.
* Academic research: a Colorado State University dissertation on automation obsolescence in heavy industry, later published in the journal Systems Engineering.
* Analyst and vendor material: ARC Advisory Group, Microsoft's lifecycle pages, Rockwell Automation, and Armis, with each commercial stake stated at each use.

Three rules applied throughout. Each figure stays tied to its population, unit, and year. Nothing is summed or converted across sources. A figure appears only if a named source page prints it.

## What Government Sources Measure

### Eleven federal systems, $754 million a year

The Government Accountability Office reviewed 69 federal legacy IT systems in 2025 and selected the 11 most in need of modernization. They range from 23 to 60 years old, and GAO reported that they collectively cost approximately $754 million annually to operate and maintain. Eight of the 11 use outdated programming languages, and seven operate with known cybersecurity vulnerabilities.

Four of the 11 rely on hardware, software, or operating systems that vendors no longer support, at the Interior Department, the Environmental Protection Agency, the Department of Homeland Security, and the Department of Transportation. For two of them, at Interior and EPA, every hardware component, software package, and operating system has lost vendor support. The Interior system supports the operation of certain dams and power plants.

The same report puts the scale of the problem in context. Federal agencies planned about $83 billion for IT operations and maintenance in fiscal year 2025, or 79% of planned IT spending. GAO's earlier review, in 2019, profiled 10 systems aged 8 to 51 years that cost about $337 million a year to run.

These are federal IT systems, so the figures describe government software and the hardware beneath it. The Interior system, which GAO describes as supporting the operation of certain dams and power plants, is the one case among the 11 that touches physical plant.

GAO's appendix profile of that system gives the most direct cost example in the report. First implemented in 2001, the system costs $2.3 million a year to operate. Modernization is estimated at $6.7 million, with potential annual savings of $750,000 from eliminating a specialized legacy support contract, and completion is planned for August 2027. GAO reported the modernization as in progress in July 2025 and described the savings as potential. The report documents no realized savings. These figures describe the operating and planned modernization costs of one legacy federal system. They do not isolate the additional costs attributable specifically to obsolescence.

### What one obsolete part costs to resolve

The Department of Defense publishes detailed guidance on the cost of parts obsolescence. Its term for the problem is DMSMS, for diminishing manufacturing sources and material shortages, and its guidebook, SD-22, was updated in January 2026.

SD-22 carries a table of average costs for each type of resolution. The figures below are reproduced in the Defense Standardization Program Journal for January to April 2021, in FY2021 dollars.

The averages rest on a 2014 survey run by the Commerce Department's Bureau of Industry and Security for the Defense Standardization Program Office. More than 50 organizations were contacted, 35 responded, and 28 responses qualified for analysis, covering 4,562 reported obsolescence issues resolved over the prior two years. The 2015 report that documents the survey states that its metrics were to be incorporated into SD-22, and its nine resolution categories match the SD-22 table. The report prints lower means with no dollar year stated: $1,028 for an approved part and $10,287,964 for a complex redesign. The resolution counts in the table above are from that report.

Two features of this table matter for anyone applying it to a plant. The sample sizes at the expensive end are small: 44 complex redesigns and 40 repair or reclamation cases. And the Defense Standardization Program Journal article that reproduces the table says actual program cost data are preferred for budgeting, with the averages as a fallback.

### Ten to fifteen years, sometimes longer

NIST Special Publication 800-82 Revision 3, the federal guide to operational technology security published in September 2023, summarizes the differences between IT and OT systems in its Table 1. Component lifetime is one of the rows: about 3 to 5 years for IT and about 10 to 15 years for OT, sometimes longer.

The same table notes that OT may run unsupported operating systems, that updates require vendor and end-user testing and scheduled outages, and that support may be limited to a single vendor. NIST does not attach a cost to any of this. It describes the conditions under which obsolescence accumulates.

### Legacy OT in critical infrastructure

Two GAO reports from 2024 describe legacy OT without pricing it. The March 2024 report on OT cybersecurity states that OT is most prevalent in 13 of the 16 critical infrastructure sectors, and a footnote says older legacy systems often run unsupported operating systems that no longer receive security patches. It also notes that OT components often must be taken offline to patch, which may not happen promptly in sectors such as energy.

The August 2024 report on water and wastewater systems adds the economic logic. Many operational technologies tied to water infrastructure are reaching the end of their design lives. Some are no longer supported by the original manufacturer, and operators keep using them because they still function and would be expensive to replace.

## Vendor Lifecycle Dates: Windows in the Plant

Microsoft's lifecycle pages supply the dates that drive much of the obsolescence conversation on plant floors, because HMIs, engineering workstations, and historians commonly run on Windows.

Windows 7 and Windows Server 2008 R2 reached end of extended support on January 14, 2020. The standard Windows 10 releases, including Home, Pro, Enterprise, and Education, reached end of support on October 14, 2025.

The long-term servicing editions that ship on many industrial PCs, HMIs, and embedded controllers follow their own dates. Microsoft's lifecycle pages give the following for the editions most likely to be found on a plant floor. Windows 10 2015 LTSB ended with the standard releases on October 14, 2025. Windows 10 2016 LTSB ended on October 13, 2026. Windows 10 Enterprise LTSC 2021 is supported through January 12, 2027. Windows 10 Enterprise LTSC 2019 and Windows 10 IoT Enterprise LTSC 2019 run through January 9, 2029, and Windows 10 IoT Enterprise LTSC 2021 through January 13, 2032. Other editions exist, so a plant that inventories its Windows hosts by edition should check each one against Microsoft's lifecycle pages, since no single date covers them all.

For organizations running the standard releases, Windows 10 Extended Security Updates cost $61 per device in year one through volume licensing. The price doubles each consecutive year, coverage is cumulative, and the program lasts a maximum of three years. Year one ended October 13, 2026, year two runs through October 12, 2027, and year three through October 10, 2028. Devices must run Windows 10 version 22H2 to be eligible, so the price applies to standard releases and does not apply to the LTSC editions above. Microsoft has announced a separate Extended Security Updates program for Windows 10 Enterprise 2016 LTSB and Windows 10 IoT Enterprise 2016 LTSB, described in a Windows IT Pro Blog post on planning for 2016 end of support, so the 2016 LTSB editions have an extended-update path of their own. The consumer option, available at no charge, for Microsoft Rewards points, or for a one-time $30, runs through October 12, 2027, and Microsoft states that it cannot be used in commercial scenarios.

## What Academic Research Found

### Obsolescence management at heavy-industry sites

A 2021 Colorado State University dissertation by Trevor Ault applied a risk-based obsolescence management method across 14 large automation upgrades and about five years of continuous operation, validated at more than a dozen sites in gas processing, chemical, and power generation. The abstract reports a reduction of roughly 70% in reactive, obsolescence-driven replacements after the major upgrades and a drop of about 24% in unplanned downtime from part failures during normal operation. The work was later published as Ault and Bradley, "Risk-based approach for managing obsolescence for automation systems in heavy industries," Systems Engineering, 2022, DOI 10.1002/sys.21635.

The abstract gives no dollar figures. It measures counts of reactive replacements and downtime events at the participating sites.

## Analyst and Vendor Estimates

### ARC's $65 billion

ARC Advisory Group sells market research to automation vendors and end users. Its estimate that roughly $65 billion of installed automation systems have reached the end of their useful life is the most repeated figure in this subject, and it appears on vendor pages from Rockwell Automation, Schneider Electric, Emerson, and ABB.

We traced it to an April 2003 column in Hydrocarbon Processing by Dick Hill of ARC, which describes roughly $65 billion of installed automation systems at the end of their traditional life cycle. A February 2007 ARC white paper written by Larry O'Brien and published through Siemens gives the scope: ARC estimates a worldwide installed base of aging process automation systems, nearing the end of its useful life, valued at roughly $65 billion. ARC's own site repeated the number in October 2015, describing the combined value of the installed base of automation systems reaching the end of their useful lives as about $65 billion. A February 2017 ARC post says the estimate was made about ten years earlier and has not changed much, even though more installed systems have aged past their useful life.

So the figure is worldwide, and it describes installed value. None of the ARC documents states an age threshold or a valuation basis such as original cost or replacement cost, and none describes the method. The 2017 page's dating of the estimate to about 2007 conflicts with its appearance in print in 2003. We found no updated ARC dollar figure, including on ARC's January 2026 post on DCS modernization.

### Rockwell Automation (2024)

Rockwell Automation sells control systems and migration services. Its ninth State of Smart Manufacturing Report, conducted with Sapio Research, surveyed 1,567 decision-makers in 17 countries, 64% of them at companies with revenue above $1 billion.

Asked about the main driver of their technology investments, with multiple selections permitted, 62% of respondents selected long-term impact on the business, 57% selected top-level business objectives, and 31% selected an emergency or immediate need caused by broken, non-operational technology. The report describes the 31% as a sign of the obsolescence organizations faced in 2024. That link is Rockwell's interpretation: the survey item asks about broken technology, and broken technology is not always obsolete technology. Replacing or upgrading legacy systems ranked fifth among eight barriers to adopting smart manufacturing technology, with no percentage printed for that item.

### Armis (2023)

Armis sells asset visibility and security software. In June 2023 it reported, from the more than three billion assets tracked by its platform, that 41% of PLCs, 56% of engineering workstations, and 60% of uninterruptible power supplies had at least one unpatched critical-severity vulnerability. Four of the five riskiest OT device types ran Windows. The release describes end-of-support hardware, firmware, and operating systems as a source of that exposure.

The figures describe devices visible to one vendor's platform, with risk scored by the vendor's own method.

## Why These Figures Cannot Be Combined

Each source uses its own unit:

* Dollars per year to operate and maintain 11 named systems (GAO)
* Average dollars per resolution, by resolution type (DoD SD-22 and the 2014 survey)
* Years of component lifetime (NIST)
* Dollars per device per year of extended support (Microsoft)
* Percentage change in reactive replacements and downtime events at participating sites (Ault)
* Dollars of worldwide installed value, with no method or age threshold published (ARC, 2003 to 2007)
* Share of survey respondents (Rockwell)
* Share of devices visible to one platform (Armis)

They also describe different populations: federal IT systems, defense programs, OT in general, Windows devices, a dozen heavy-industry sites, and respondents or devices seen by individual vendors.

When quoting any of these figures, state the source, the unit, the population, and the year.

## At a Glance

## Honest Limitations

* **No national cost series.** The sources reviewed do not provide a dollar cost of obsolete automation for U.S. industry, and this guide does not construct one.
* **The GAO figures are federal IT.** Only one of the 11 systems directly supports physical plant. The $754 million describes government software and hardware, and it should not be read as an industrial benchmark. The $750,000 savings figure for the Interior system is GAO's reported potential saving, projected before modernization is complete.
* **The DoD cost table is a defense average.** It rests on a 2014 survey of 28 organizations resolving obsolescence in DoD programs. The expensive categories have small samples, and the journal article that reproduces the table recommends actual program data over the averages.
* **The ARC figure has a scope and no method.** It appears in print in 2003, a 2007 ARC white paper describes it as worldwide, and ARC's site repeats it in 2015 and 2017. No ARC document we located states an age threshold, a valuation basis, or a method, and ARC's own 2017 dating of the estimate conflicts with the 2003 appearance.
* **The Windows 10 dates depend on edition.** The October 14, 2025 date and the $61 ESU price apply to standard releases on version 22H2. The selected LTSB and LTSC editions in this guide run from October 2025 to January 2032, the list is not exhaustive, and a plant's Windows exposure depends on which editions it runs.
* **The academic result is site-specific.** Ault's figures describe counts at the participating sites before and after major upgrades, and the dissertation abstract prints no costs.
* **The vendor figures describe each vendor's own view.** Armis reports on devices its platform sees. Rockwell's 31% comes from a select-all-that-apply question about broken technology, and the obsolescence framing is Rockwell's.
* **The NIST lifetime figure is a typical range.** NIST describes it as a typical difference, and individual systems run shorter or much longer.
* **BEA average-age data were not used.** The Bureau of Economic Analysis publishes current-cost average age of private equipment by industry. We could not open the interactive tables during research, so no equipment-age figure appears here.
* **Nothing is adjusted.** This guide does not convert any figure for inflation or scale it to plant size.

## Frequently Asked Questions

### How much does obsolete automation cost manufacturers?

The published figures come in pieces. The Department of Defense prices a single obsolescence resolution at $1,165 to about $11.65 million depending on the fix, in FY2021 dollars. GAO puts the operating cost of 11 critical federal legacy systems at about $754 million a year. The most repeated figure, about $65 billion of installed automation at the end of its useful life, is an ARC Advisory Group estimate of worldwide installed value that appeared in print in 2003 and has been restated since without a method, age threshold, or update. No source reviewed provides a national dollar cost for U.S. manufacturing, and the figures cannot be added together.

### Where does the $65 billion obsolete automation figure come from?

It comes from ARC Advisory Group. The earliest appearance we located is an April 2003 column in Hydrocarbon Processing by an ARC analyst. A February 2007 ARC white paper describes it as the value of a worldwide installed base of aging process automation systems nearing the end of its useful life. ARC's own pages repeated the figure in October 2015 and February 2017, the latter saying the estimate was about ten years old and had not changed much. None of the documents states an age threshold, a valuation basis, or a method, and we found no updated ARC dollar figure.

### How long do industrial control systems last?

NIST SP 800-82 Revision 3 gives a typical lifetime for OT components of about 10 to 15 years, sometimes longer, compared with about 3 to 5 years for IT components. That is a component figure, and a complete control system can outlast the components that make it up as parts are replaced. GAO reported in 2025 that the 11 most critical federal legacy systems are 23 to 60 years old, and one of them supports the operation of certain dams and power plants on hardware and software the vendors no longer support, at an operating cost of $2.3 million a year.

### What does it cost to keep Windows 10 after end of support?

Microsoft ended support for the standard Windows 10 releases on October 14, 2025. For organizations, Extended Security Updates cost $61 per device in year one through volume licensing, with the price doubling each year for a maximum of three years. Year one ended October 13, 2026. Devices must run version 22H2, and Microsoft states that the consumer ESU option cannot be used in commercial scenarios. The long-term servicing editions common on industrial PCs have separate dates: Enterprise LTSC 2021 through January 12, 2027, IoT Enterprise LTSC 2019 through January 9, 2029, and IoT Enterprise LTSC 2021 through January 13, 2032.

### How many PLCs have unpatched vulnerabilities?

Armis, a security vendor, reported in June 2023 that 41% of PLCs tracked by its platform had at least one unpatched critical-severity vulnerability, along with 56% of engineering workstations and 60% of uninterruptible power supplies. The figures describe devices visible to one vendor's platform.

### Does managing obsolescence proactively reduce downtime?

One academic study reports an association. A 2021 Colorado State University dissertation, later published in Systems Engineering, applied a risk-based obsolescence management method across 14 large automation upgrades at more than a dozen gas processing, chemical, and power generation sites. It reports roughly 70% fewer reactive, obsolescence-driven replacements and about 24% less unplanned downtime from part failures after the major upgrades. The abstract prints no dollar figures.

## Related Guides

* [Industrial Equipment's Lifetime Ownership Costs](https://reliamag.com/topics/guides/industrial-equipment-lifetime-ownership-costs)
* [Manufacturing Cyberattack Costs and Recovery Times](https://reliamag.com/topics/guides/manufacturing-cyberattack-costs-recovery-times)
* [Best SCADA and HMI Software](https://reliamag.com/topics/guides/best-scada-hmi-software)
* [Reactive Maintenance Costs 3 to 5x More: Tracing the DOE Claim](https://reliamag.com/topics/guides/reactive-maintenance-cost-multiplier)
* [Deferred Maintenance Backlog Statistics](https://reliamag.com/topics/guides/deferred-maintenance-backlog-statistics)

## Sources

* Government Accountability Office. [Information Technology: Agencies Need to Plan for Modernizing Critical Decades-Old Legacy Systems](https://www.gao.gov/products/gao-25-107795) (GAO-25-107795, July 2025, including the Appendix IV system profiles; the 2019 figures are from GAO-19-471, and the OT and water findings are from GAO-24-106576 and GAO-24-106744).
* Defense Standardization Program Office. [Defense Standardization Program Journal, January to April 2021](https://www.dsp.dla.mil/Portals/26/Documents/Publications/Journal/210401-DSPJ.pdf) (Mandelbaum and Patterson, Table 1, average DMSMS resolution costs in FY2021 dollars; SD-22 updated January 2026).
* U.S. Department of Commerce, Bureau of Industry and Security. [DMSMS Resolution Cost Metrics Report](https://www.bis.gov/media/documents/dmsms-cost-metrics-report-2015-final.pdf) (2014 survey for the Defense Standardization Program Office, released March 2015).
* National Institute of Standards and Technology. [SP 800-82 Rev. 3, Guide to Operational Technology (OT) Security](https://csrc.nist.gov/pubs/sp/800/82/r3/final) (September 2023; Table 1).
* Microsoft. [Windows 10 Extended Security Updates](https://learn.microsoft.com/en-us/windows/whats-new/extended-security-updates) (ESU pricing and terms; lifecycle dates from Microsoft's product lifecycle pages; the 2016 LTSB program is described in the Windows IT Pro Blog post "Plan for Windows Server 2016 and Windows 10 2016 LTSB end of support").
* Colorado State University, Mountain Scholar. [Modernizing automation in industrial control/cyber physical systems through the system engineering lifecycle](https://mountainscholar.org/items/9e937c69-b639-4101-81b3-12a9ee5950a1) (Ault, 2021 dissertation; published as Ault and Bradley, Systems Engineering, 2022, DOI 10.1002/sys.21635).
* ARC Advisory Group. [Optimizing Process Control System Upgrade Projects](https://www.arcweb.com/blog/optimizing-process-control-system-upgrade-projects) (O'Brien, October 2015; the February 2017 restatement is the ARC blog post "Does your migration project ignore intelligent instruments?").
* ARC Advisory Group, white paper published through Siemens. [Siemens Process Automation System Migration and Modernization Strategies](https://assets.new.siemens.com/siemens/assets/api/uuid:0dd88880-2675-4f58-abf5-ad8082c58fd8/migration-whitepaper-en.pdf) (O'Brien, February 2007; describes the $65 billion installed base as worldwide).
* Hydrocarbon Processing. [Ten questions for your process automation system migration partner](https://hydrocarbonprocessing.com/magazine/2003/april-2003/columns/hp-integration-strategies-ten-questions-for-your-process-automation-system-migration-partner) (Hill, ARC Advisory Group, April 2003; paywalled preview).
* Rockwell Automation. [9th Annual State of Smart Manufacturing Report](https://www.rockwellautomation.com/content/dam/rockwell-automation/documents/pdf/campaigns/state-of-smart-2024/9th-annual-state-of-smart-manufacturing-report-en.pdf) (2024; vendor survey with Sapio Research).
* Armis. [Armis Identifies Riskiest OT and ICS Devices Across Critical Infrastructure Industries](https://www.armis.com/newsroom/press/armis-identifies-riskiest-ot-and-ics-devices-across-critical-infrastructure-industries/) (June 2023; vendor platform data).