The short answer
Why this keeps happening: design life is not operating life
Published design lives are modest and real service lives are long. Vendor field data, indicative rather than audited, put end-suction centrifugal pumps at 20 to 25 years of design life, planetary gearboxes at 20 to 30, rotary screw compressors at 10 to 20, and rail electrical and mechanical systems at 20 to 40. In practice internal-gear pumps are found at 40 years and more, and the academic estimate of average machinery lifetime in Dutch manufacturing is about 26 years, within a literature range of 15 to 34. Nothing in that machinery is designed to be supported for that long.
The supply side is moving the other way. European machine-tool consumption fell 17.1 per cent in 2024 according to the industry bodies CECIMO and the MTA, with a further fall projected for 2025, which means operators are keeping older machines running rather than buying new ones. German mechanical-engineering insolvencies rose by about a third in 2024 on Creditreform and Allianz Trade data. Every insolvency strands an installed base, and the drawings, tooling and parts stock of the failed company are frequently scrapped rather than sold on.
The discipline that deals with this has a name and a standard. Obsolescence management, defined in IEC 62402:2019 and its UK mirror BS EN IEC 62402:2019, is the practice of anticipating and resolving the point at which an item can no longer be procured from its original source. The US defence term is DMSMS, diminishing manufacturing sources and material shortages, handled under the Department of Defense guidebook SD-22. The UK has had a cross-industry Component Obsolescence Group since 1997.
What the law does, and what it does not
Owners of industrial plant sometimes assume a parts-availability rule exists. For consumer goods, one now does. The EU Right to Repair Directive, Directive (EU) 2024/1799, in force from July 2024 and applying from 31 July 2026, and the Ecodesign product regulations require manufacturers of defined consumer categories to keep spare parts available for seven to ten years after the last unit is placed on the market. None of that reaches a press, a pump or a machining centre.
The EU Machinery Regulation, Regulation (EU) 2023/1230, which replaces the Machinery Directive, goes further the other way and explicitly excludes spare parts from its scope except for safety components supplied by the original manufacturer to replace identical ones. The UK has no horizontal parts-availability law for industrial machinery either. The practitioner rule of thumb, parts for about seven years after end of production, is custom, widely ignored, and often ended early because holding the stock creates liability and accounting cost. Sector rules in rail, aerospace and medical devices impose through-life support, but by contract, not by statute. In short: for plant and machinery, the asset owner carries the obsolescence risk, and only a contract shifts it.
The cost ladder: why timing is worth more than technique
The best independent cost data on resolving obsolescence comes from a 2014 US Bureau of Industry and Security survey published in the DoD SD-22 guidebook. Average cost per resolution, in US dollars, rises by three orders of magnitude from the cheapest route to the most expensive:
| Resolution | Average cost (USD, DoD SD-22) |
|---|---|
| Approved alternative part already exists | $1,028 |
| Life-of-need buy (buy the remaining stock) | $5,234 |
| Simple substitute part | $12,579 |
| Complex substitute part | $25,410 |
| Extension of production or support | $25,472 |
| Repair, refurbish or reclaim | $65,015 |
| Develop a new item or new source (reverse engineer) | $655,411 |
| Redesign the next higher assembly | $1,092,856 |
| Redesign or replace the complex system | $10,287,964 |
Two cautions. These figures include military qualification and certification costs, so they are upper bounds; a simple mechanical spare is far cheaper to re-engineer in civilian practice. And the ladder is not a menu: the cheap rungs are only available before the part disappears. The UK Ministry of Defence's own study with QinetiQ and ARINC found sourcing a substitute part averaged about £13,500 while a major redesign exceeded £300,000, before any downtime cost.
Downtime is where the real money is. ABB's 2023 survey of over 3,000 plant maintenance decision-makers put the median cost of unplanned downtime at about $125,000 an hour, and Siemens' 2024 study put automotive at up to $2.3 million an hour. Those are vendor figures and should be read as indicative. The peer-reviewed anchor is that unplanned downtime costs three to five times planned maintenance. Either way, a £13,500 substitute part is cheap against a line that stops.
The eight options when a part is no longer available
| Option | Typical cost | Lead time | Risk | When it is right |
|---|---|---|---|---|
| Last-time buy from the OEM | Lowest, if the part is still in production | Weeks | Over-buy ties up capital; under-buy leaves a stockout | Known, finite demand |
| OEM legacy pricing or a broker | Two and a half times normal for a last-time buy; five to ten times for obsolete stock | Weeks to months | Lock-in; counterfeit and traceability risk on the grey market | Rarely right; a forced position |
| Reverse engineer and remake | A fraction of the defence-grade figures above for simple mechanical parts | Weeks | Per-part IP check; chance to upgrade the material | Mechanically understood part, recurring need |
| Repair, refurbish or remanufacture | Remanufacture saves 20 to 80 per cent of the cost of new (Lund, 1984) | Days to weeks | Residual-life uncertainty | The core is salvageable |
| Additive manufacture from a digital file | Deutsche Bahn: ten months to two for a gearbox housing | Days to weeks | Certification limits on load-bearing metal parts | Low volume, geometry known |
| Retrofit the controls or drive | Far below a full rip-and-replace | Weeks to months | Integration | Control obsolescence on a sound machine |
| Replace the machine | 100 per cent of new | Months to a year | Capital, disruption | Repair above half of replacement and the asset past design life |
| Cannibalise or buy surplus | Variable | Days | Quality and traceability | A bridge to a permanent fix, never the fix |
The two options that most UK asset owners under-use are reverse engineering and remanufacture, and both are cheaper than the ladder suggests once the defence overhead is stripped out. Our practical guides cover them in detail: how an obsolete part is remanufactured and how a part is reverse engineered from a sample with no drawing. Where the obsolete item is a catalogue part that only needs a feature added, modifying a standard part is faster than either.
Decision rules that maintenance teams actually use
- The 50 per cent rule. If a single repair exceeds half the current replacement cost, replace. Widely applied across industrial, HVAC and fleet maintenance.
- Cumulative thresholds. Annual maintenance above 25 per cent of replacement cost: plan replacement within twelve months. Asset age above 80 per cent of design life: start the capital plan. A critical part reaches end of life with no source: resolve immediately, do not wait for the failure.
- Whole-life cost, not purchase price. ISO 55000 and ISO 55001, revised in 2024, and the IEC 60300 life-cycle costing methods separate economic life from physical life. A machine can be physically fine and economically dead, or the reverse.
- Insurance spares on impact, not price. An expensive part that fails once in five years is not critical. A cheap part that fails monthly and stops the line is. Stock on expected downtime avoided against carrying cost; the often-quoted 20 to 30 per cent annual carrying figure is inherited from general logistics and has never been measured for spares, so use your own number.
Secure the data before it disappears
The cheapest moment to solve an obsolescence problem is while a physical part still exists and the drawing still might. Four things to do now for every orphaned critical asset:
- Scan and draw the wear parts while you have a sample, worn or not. A replacement part solves this failure; a drawing solves every future one.
- Write escrow into new machinery contracts: drawings and manufacturing data packages released to you if the supplier ceases to trade or ends support.
- Watch the OEM's health. Product change and discontinuation notices, and the supplier's credit rating, belong in the same register as the parts.
- When an OEM liquidates, bid for the tooling, drawings and stock before they are scrapped. This is routinely the best money an asset owner spends.
On the legal position: under UK law, functional spare parts are largely excluded from unregistered design right by the must-fit and must-match exclusions in the Copyright, Designs and Patents Act 1988, so a replacement part can generally be lawfully reverse engineered. Live patents, copyright in the original drawings and trade secrets can still apply, so the check is per part, and worth a short conversation with an IP adviser before a recurring remake.
What good looks like: four cases
- Deutsche Bahn has printed more than 100,000 parts since 2015; the hundred-thousandth was a 570 kg locomotive gearbox housing whose conventional lead time of about ten months fell to two, per Global Railway Review, May 2023. Its digital warehouse holds about 1,000 models.
- Angel Trains and Chiltern Railways replaced an obsolete grab handle on a thirty-year-old fleet whose supplier no longer existed. New tooling would have cost up to £15,000 with a ten-week lead; the part was printed in three weeks in a material certified to the rail fire standard EN 45545-2 (Stratasys case study, 2020).
- Power generation: the Electric Power Research Institute put an obsolete control-system rip-and-replace at about $4 million, with one utility expecting $6 to 8 million per project, which is the case for phased retrofit on a mechanically sound plant.
- The NHS estate shows what deferred obsolescence looks like at scale: England's maintenance backlog reached £15.9 billion in 2024/25 on the NHS ERIC data, up 15.7 per cent in a year, with £5.6 billion classed as significant risk.
A four-stage plan for a UK site
- Triage, now. Run every critical spare against the OEM's live catalogue and flag anything marked end of life, last-time buy or contact factory. Segment the installed base by criticality, obsolescence risk and lead time. Escalate any single point of failure whose OEM is insolvent, acquired or shaky, or whose lead time exceeds the downtime you can tolerate.
- Secure the data, within months. Scan and draw orphaned critical parts; negotiate escrow; evaluate buying liquidated tooling.
- Choose each resolution on the economics. The 50 per cent rule and whole-life cost. Reverse engineer or remanufacture mechanically sound parts with clear IP; retrofit controls on sound machines; replace only where repair exceeds half of new and the asset is past design life.
- Institutionalise. Adopt IEC 62402 under ISO 55000, keep an obsolescence register with change-notice and credit monitoring, and benchmark maintenance spend: best-in-class operators spend about 3.5 per cent of replacement asset value on maintenance, repair and operations against an average of 5.2 per cent, on Aberdeen data.
Where TrueNorth fits
Stages two and three are our work. Send the worn part, with or without a drawing, and TrueNorth measures it, produces the manufacturing drawing and model, and makes it through a vetted UK network, with material certificates and inspection records for the traceability file, from quantity one. We tell you when a part is not worth remaking, and when a standard catalogue part with one modification will do instead. What we do not do is pretend to hold an OEM's drawings; the drawing we make becomes yours.
Obsolescence: the questions asset owners ask
Treat the machine as orphaned immediately. List its critical wear parts, get each measured and drawn while a sample exists, check whether the liquidator is selling tooling, drawings or stock, and decide each part's route on cost and lead time before it fails. A reverse-engineered mechanical spare is usually a fraction of the cost of the forced redesign or emergency broker purchase you face after the failure.
For industrial machinery, there is no legal minimum in the UK or the EU. The EU Right to Repair Directive and Ecodesign rules require seven to ten years of parts availability only for defined consumer product categories, and the EU Machinery Regulation excludes spare parts from its scope. The seven-year practitioner rule of thumb is custom, not law. Only a contract, for example an escrow or support clause, obliges an OEM to keep supplying parts for plant.
Usually repair, until one of two thresholds is crossed: a single repair above half the replacement cost, or annual maintenance above a quarter of replacement cost with the asset past 80 per cent of its design life. Remanufacture saves 20 to 80 per cent of the cost of new on the peer-reviewed evidence. Run the whole-life cost rather than the purchase price, and check whether a new unit's efficiency in use would outweigh the saving.
Eight, in rising order of cost and disruption: a last-time buy of remaining stock, OEM legacy or broker pricing, reverse engineering and remaking, repair or remanufacture of the existing part, additive manufacture from a digital file, retrofit of the controls or drive, full replacement, and cannibalising or surplus as a bridge. Which is right depends on lead time, criticality and whether the part is mechanically understood.
A last-time buy is right when demand is known and finite and the part is still in production; it costs about $5,000 on average in the US defence data. Reverse engineering is right when the need recurs, the part is mechanically understood and the IP is clear, because the drawing you gain solves every future failure. Over-buying ties up capital in stock that may never be used; under-buying leaves a stockout.
Generally yes. Functional spare parts are largely excluded from unregistered design right by the must-fit and must-match exclusions in the Copyright, Designs and Patents Act 1988. Live patents, copyright in the original drawings and trade secrets can still apply, so the check is per part. TrueNorth reverse engineers from the physical part and does not use or claim any OEM drawings.
Obsolescence management is the discipline of anticipating and resolving the point at which an item can no longer be procured from its original source, across the whole life of the asset. The international standard is IEC 62402:2019, adopted in the UK as BS EN IEC 62402:2019, and it sits alongside ISO 55000 for asset management and IEC 60300 for life-cycle costing. The US defence equivalent is DMSMS under the DoD SD-22 guidebook.