Tools & Data Method · Definitions

DMSMS vs obsolescence: what it means for your parts

Hermann Njike

Method · 12 min read

Method

DMSMS, losing your source of supply Obsolescence, one cause of that

DMSMS stands for diminishing manufacturing sources and material shortages: the loss, or impending loss, of the last known manufacturer or supplier of the parts or materials your design still depends on. Obsolescence is one cause of that condition, and only one of several. That distinction is worth getting right first, because the two words get used for each other, and the difference between them is practical. This page defines DMSMS in plain terms, separates it from obsolescence, lists what actually triggers it, and shows how it plays out at the component level, from the first change notice to the decision to buy, substitute, or redesign. It is written for the engineer who owns aging hardware in any industry, not only defense, and it is editorially independent and recommends no tool.

Definition // The standing condition

What DMSMS means

DMSMS is a standing condition. It persists until the loss of supply is resolved. It describes the situation where the manufacturers of a part, or the materials that part is made from, are no longer available to you while your design still needs the part. The term comes from United States Department of Defense sustainment practice, where it is the standard name for the loss-of-source problem on hardware that has to stay buildable for decades.

The condition is not unique to defense. IEC 62402, the international obsolescence-management standard, applies to any organization and any long-life product, in medical, industrial, rail, energy, or telecom, the moment a supplier stops making a part still on the bill of materials. The acronym names two ways you can lose the part:

Diminishing manufacturing sourcesThe supply side01

The manufacturers who make the part stop making it, or stop selling it to you.

Material shortagesThe materials side02

A raw material or process input becomes unavailable or restricted, so the part cannot be made even if a manufacturer would.

Both are in one term because the response is the same. Whether you lost the maker or the material, you have a part on your BOM you can no longer buy, and you have to do something about it.

Distinction // Two different conditions

DMSMS vs obsolescence: the difference

Obsolescence and DMSMS are used interchangeably, but they describe different conditions.

ObsolescenceA status of the part. The part is no longer manufactured or supported, it has reached end of life. It is one specific cause.

DMSMSThe broader condition of losing your source of supply, from any cause. Obsolescence is one trigger, but a material restriction, a plant closure, an allocation, or a manufacturer choosing to stop selling to your market all produce DMSMS without the part being formally obsolete anywhere.

The costly mistake is treating the two as the same question. Ask only whether a part is obsolete and you miss every DMSMS case where it is not obsolete anywhere: a plant closure, a newly restricted material, a maker that stopped selling to your market, or a part still listed as available that no longer works as intended in your system (what DoD sustainment practice calls functional obsolescence). The question that actually protects you is broader: can I still get, and still use, the part I qualified, from a source I trust?

	Obsolescence	DMSMS
What it is	A status of the part: no longer manufactured or supported	The condition of losing your source of supply, from any cause
Scope	One specific cause	The whole condition; obsolescence is one trigger among several
Still-orderable case	Obsolete means the maker no longer produces it, though existing stock may still be buyable	You can still have a DMSMS problem on a part that is technically available (functional obsolescence)
The question it answers	Is this part still made?	Can I still get, and still use, the part I qualified, from a source I trust?

Triggers // Recurring causes

What can cause a DMSMS shortage

The triggers cluster into a few recurring causes:

Manufacturer exitThe maker discontinues the part, exits the product line, or leaves the market, sometimes after a merger consolidates overlapping product lines.

Process-node retirementA foundry retires an older process node, ending everything built on it.

Material or regulationA raw material becomes scarce, or a regulation restricting a substance bans a material or finish, forcing a change or an end of life. The REACH restriction proposal on PFAS, submitted by five national authorities, names electronics and semiconductors among the uses in scope, the kind of market-wide substance action that can push a maker to reformulate or discontinue a part otherwise still in production.

Allocation & demand shiftCapacity moves to higher-volume parts, and a low-volume legacy part is starved even while nominally active.

None of these is under the control of the engineer who depends on the part. DMSMS management is the work of responding to that loss through the part on the BOM.

Workflow // Four stages, four signals

How DMSMS shows up at the component level

This is where the sustainment vocabulary becomes the parts workflow every obsolescence owner runs, whatever the industry. Four stages, each with a specific signal you read and a decision it forces:

A change notice arrives, or it does not
The signal is a PCN (product change notice) or a PDN (product discontinuation notice) from the manufacturer, and it is where the last-time-buy date lives. J-STD-048A (which supersedes JESD48) governs timely notification of planned product discontinuance. The catch: many discontinuations carry no notice at all. In one aggregator's tracking (Z2Data), a large share of parts that go obsolete carry no product change notification, so the first signal is often a distributor lifecycle flag flipping, not a PCN.
The part moves through lifecycle states
The field to watch is the manufacturer's own lifecycle status. Texas Instruments, for one, publishes each product as preview, active, not recommended for new designs (NRND), last time buy, or obsolete, so a part is commonly marked NRND before it reaches last-time-buy and obsolete. J-STD-048A standardizes the discontinuance notice, not these status labels, so the same stage can read differently on two makers' pages.
A last-time-buy window opens
The artifact is the last-time-buy date on the PCN or PDN. Buying to that date bridges supply, but it only defers the decision, and stored parts do not keep indefinitely: for moisture-sensitive surface-mount devices, J-STD-033 sets a minimum dry-pack shelf life of 12 months from the seal date, one worked example of the storage limits that cap how far a bridge buy can reach.
You choose a response
The options are a bridge buy, a qualified second source, an authorized-aftermarket source, a suggested substitute to validate, or a redesign. Each carries a different cost and requalification burden, and the right one depends on the system, not the part alone.

DMSMS management is the discipline of running that sequence deliberately, ideally before the notice arrives rather than after stock runs out.

Process // Reactive vs proactive

The DMSMS management process

DoD policy names two approaches, reactive and proactive, and prescribes the proactive one.

Reactive

Responds after a part is already gone: find stock, find a substitute, or redesign under time pressure.

The most expensive mode

Proactive

Monitors the BOM for at-risk parts, forecasts which are heading for end of life, and acts while options are still open and cheap.

Prescribed by DoD policy

The formal artifact is a DMSMS management plan, called an obsolescence management plan (OMP) in IEC 62402: a documented process for monitoring, assessing, and resolving losses of supply across a product's life. The governing DoD instruction directs organizations to develop and maintain a plan that documents the processes and team structures needed to identify DMSMS risks, assess the potential impact on schedule or readiness, analyze the mitigations, and implement the optimal resolution. SD-22 (January 2016) describes how to develop a DMSMS management plan in Section 3.2.

A DMSMS program office, in organizations large enough to have one, owns this process. It runs the monitoring, coordinates the response across engineering and procurement, and maintains the plan.

References // The governing documents

The standards that govern it

Two public documents anchor DMSMS and obsolescence-management practice:

SD-22

The DMSMS Guidebook (January 2016 edition). The DoD public guide to DMSMS management: definitions, causes, the management process, and resolution options. A Defense Standardization Program document under DoDI 4245.15, publicly available, not restricted.

IEC 62402:2019

Obsolescence management. The international standard for managing obsolescence across a product's life. Its scope applies to any organization that depends on another for the items it uses, which is why it is used in commercial and industrial sectors, not only defense.

SD-22 puts interchangeability at the center of substitution. Its resolution-options guidance (Table 9) defines a simple substitute as an existing item that meets all requirements without modification and needs only minimal qualification, a fit, form, and function substitute. SD-22 also uses the fuller "form, fit, function, and interface" criterion in its replacement-specification language. Either way, that interchangeability test is why the substitution question sits at the center of DMSMS work, and it is the subject of the form, fit, function reading linked below.

FAQ // Frequently asked

Frequently asked questions

What does DMSMS mean, and what does DMSMS stand for?

DMSMS stands for diminishing manufacturing sources and material shortages. It is the loss, or impending loss, of the last known manufacturer or supplier of the parts or materials your design still needs.

DMSMS vs obsolescence: what is the difference?

Obsolescence is one status of a part, no longer manufactured or supported. DMSMS is the broader condition of losing your source of supply from any cause, including obsolescence but also material restrictions, plant closures, allocation, or a manufacturer leaving your market. You can have a DMSMS problem on a part that is still available but no longer works as intended in your system.

What can cause a DMSMS shortage?

Manufacturer exit or discontinuation (sometimes after a merger consolidates product lines), process-node retirement, material unavailability or regulation restricting a substance, and allocation or demand shift away from low-volume parts.

What is the DMSMS management process?

Monitoring the bill of materials for at-risk parts, assessing which are heading for end of life, and resolving each loss through a set of options: last-time-buy, second source, authorized aftermarket, substitution, or redesign. DoD policy prescribes doing this proactively, which is far cheaper than reacting after stock is gone.

What is the role of the DMSMS program office?

In organizations that have one, it owns the monitoring, coordinates the response across engineering and procurement, and develops and maintains the DMSMS management plan.

What are the requirements for DMSMS management?

Four things in practice: a documented management plan, continuous monitoring of the bill of materials for at-risk parts, a risk assessment of each part heading for end of life, and a defined resolution process (last-time-buy, second source, authorized aftermarket, substitution, or redesign). The governing standard or contract, commonly SD-22 or IEC 62402, sets which are mandatory and how they are documented.

References // Public sources

Sources

Related // Keep reading

Method · The interchangeability testForm, fit, function: when a replacement part actually is one

The substitution question sits at the center of DMSMS work. This is the test that decides whether a candidate is actually a replacement in your system, not just a cross-reference match.

Editorially independent and from public sources only; lifecycle, standards, and status data is vendor- or publisher-reported, not independently audited. Definitions follow SD-22 and IEC 62402, confirm the governing standard for your program before relying on it.

About the author

Hermann Njike is a systems obsolescence manager who leads the cross-functional response when critical components go end-of-life, and is the single point of contact for thousands of production parts.