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Chapter 01Materials ManagementArticle 1.3

Obsolescence and Alternative Material Logic

Obsolescence is not only a purchasing problem. It is a lifecycle risk linking equipment, stock, technical equivalence and future maintenance demand.

Lifecycle management · Technical equivalence5 min readDecision Lab available

  1. ProblemThe original part is no longer available and a replacement is offered.
  2. SignalsIdentity, compatibility, specification, certificates, BOM, existing stock.
  3. DecisionSupported, clarify, engineering review, or not supported.
  4. ControlData, BOM and old stock updated together.

01Business problem

Sooner or later a manufacturer stops making a part. The notice may come from the OEM, from a supplier quoting a different part number, or from a requisition that simply cannot be bought anymore.

At that moment two problems appear at once. Maintenance still needs a part that fits and works in the installed equipment. And the plant still holds stock, data and BOM links built around the old item. If only the first problem is solved, the plant ends up with a new part that nobody can find through the equipment and an old part that nobody will ever use.

02Core concept

An alternative material is not automatically an interchangeable material.

Interchangeability has to be shown, not assumed. The professional questions are:

  • Form: same dimensions, connections and mounting?
  • Fit: does it install in the same place without modification?
  • Function: same performance under the actual operating conditions?
  • Material and specification: same or better material, rating and standard?
  • Certification: does it carry the documents the original required?
  • Manufacturer approval: is the change supported by the OEM or by engineering?
  • Lifecycle support: will the replacement itself remain available?

Then the data side: existing stock of the old item, the BOM entries that point to it, and a master-data record that must not become a duplicate.

03Decision rule

Accept a replacement only when identity, compatibility and the required evidence are established, and carry the decision through to master data, BOM and the old stock.

Where compatibility depends on engineering judgement, the materials role prepares the evidence and the question. The technical decision belongs to the engineering authority.

04Signals and inputs

Manufacturer status
Obsolescence notice or confirmed end of supply.
Old and new part numbers
The exact identities being compared.
Technical attributes
Dimensions, material, rating, connections.
Compatibility evidence
OEM statement, datasheet comparison or engineering opinion.
Certificate requirement
Documents the application requires.
Equipment relationship
Which equipment, and how many units, use the part.
Existing stock
Quantity and condition of the old item.
BOM status
Where the old item is linked and must be updated.

05Model

Lifecycle decision chain
  1. 01Obsolescence signalOEM notice, supplier substitution or a failed purchase.
  2. 02Proposed replacementNew part number or alternative manufacturer.
  3. 03Identity checkManufacturer, part number and description confirmed.
  4. 04CompatibilityForm, fit and function against the installed equipment.
  5. 05Technical requirementsMaterial, rating and operating conditions.
  6. 06Certificates and documentationEvidence required for the original is available for the replacement.
  7. 07Engineering decisionTechnical acceptance by the responsible authority.
  8. 08Master data and BOMRecord created or linked once, BOM updated.
  9. 09Old stock dispositionUse up, keep for remaining equipment, transfer or dispose.

06Worked example

Illustrative example

A seal kit at end of supply

An OEM announces that a pump seal kit is discontinued. A supplier offers a kit from another manufacturer and describes it as equivalent.

  • Identity: the new manufacturer and part number are clear.
  • Compatibility: dimensions match the old kit on the datasheet; the elastomer material is different.
  • Evidence: there is no statement from the pump OEM; the material certificate covers the new kit only.
  • Data: the old kit is linked to the BOM of three pumps, and 6 kits remain in stock.

Result: engineering review is required, and until its decision is recorded the replacement is not supported. The different elastomer is a technical question for engineering, not a materials decision. Meanwhile the remaining kits keep the old BOM link, and the new part is not created as a separate record until the decision is made.

07Professional judgement

A supplier's "equivalent" is a claim, not a conclusion.

It is the start of the evaluation. Matching dimensions do not prove matching function, and a different material can behave very differently at the actual temperature, pressure or process medium.

The materials role is to make the question precise: what changed, what evidence exists, which equipment is affected and what happens to the stock and the data. The decision on technical acceptability belongs to engineering. Keeping that boundary clear is part of the control, not a delay.

08Failure modes

  • Supplier says equivalent without evidence

    A part that fits but does not perform is installed.

    ControlAsk for datasheets, OEM statements or an engineering review.

  • New part accepted, BOM not updated

    Planners cannot find the replacement through the equipment.

    ControlUpdate BOM links as part of the decision.

  • Old stock left without disposition

    Obsolete stock stays active and is reordered or written off later.

    ControlDecide use-up, retention, transfer or disposal.

  • Replacement creates a duplicate

    Stock and demand split across two records.

    ControlSearch existing records before creating a new one.

  • Certificate differences ignored

    The replacement cannot be used where documentation is mandatory.

    ControlCompare the required documents for both items.

  • Compatibility assumed from description

    The short text matches; the part does not.

    ControlCompare manufacturer data, not descriptions.

09Field note

10Practical checklist

  • Obsolescence confirmed with the manufacturer or supplier.
  • Old and new identities documented: manufacturer, part number, attributes.
  • Form, fit and function compared against manufacturer data.
  • Certificate and documentation requirements compared.
  • Engineering decision requested where compatibility is in doubt.
  • Existing records searched before a new material is created.
  • BOM links and old-stock disposition decided together.

11Try the decision logic

Decision Lab

Obsolescence and alternative

The OEM part is obsolete. Is the proposed replacement supported?

Try the decision logic. There is no score: choose a decision and compare it with a professional review.

  1. 01Situation

    Illustrative scenario

    The OEM has discontinued a spare used in installed equipment, and a replacement with a new part number is proposed. Inspect the evidence and decide what the materials review can support. Technical acceptance of a replacement belongs to engineering.

    Old item
    OEM part, discontinued
    Proposal
    New part number for the same position

  2. 02Signals

    • Who proposes the replacementThe OEM, as a superseding part number · A supplier, from another manufacturer
    • Compatibility evidenceForm, fit and function confirmed by manufacturer data · Dimensions match, one attribute differs · Description only
    • DocumentationSame documents available · Different or missing documents
    • Equipment relationshipLinked to the BOM of the installed equipment · Not linked to any equipment
    • Old stockNone left · Old stock remains
    • BOM and master dataUpdate prepared · Not addressed

  3. 03Decision

    • Replacement supported
    • Clarification required
    • Engineering review required
    • Alternative not supported

  4. 04Professional review

    The interactive review needs JavaScript. Without it, the complete logic is in the rules below.

How the review is reached

The rules are checked from the top; the first one that matches the signals gives the professional position. Values in square brackets are filled in with the calculated numbers.

  1. IfCompatibility evidence: Description only

    Professional positionAlternative not supported

    ConditionalClarification required

    Any other decision: not supported by the signals

    Compatibility rests on a description only. Short text is not evidence of form, fit and function, so the replacement is not supported until manufacturer data is provided.

  2. IfEquipment relationship: Not linked to any equipment

    Professional positionClarification required

    ConditionalEngineering review required

    Any other decision: insufficient information

    The part is not linked to the equipment it serves. Without knowing which equipment, and how many units, use it, compatibility cannot be assessed.

  3. IfCompatibility evidence: Dimensions match, one attribute differs

    Professional positionEngineering review required

    ConditionalClarification required

    Any other decision: escalation required

    Dimensions match but one attribute differs. Whether the difference matters in this application is an engineering decision, outside the materials role.

  4. IfDocumentation: Different or missing documents

    Professional positionClarification required

    ConditionalEngineering review required

    Any other decision: not supported by the signals

    The replacement does not carry the same documents as the original. Where documentation is required, the gap has to be closed before the replacement can be used.

  5. IfWho proposes the replacement: A supplier, from another manufacturer

    Professional positionEngineering review required

    ConditionalReplacement supported

    Any other decision: escalation required

    The compatibility evidence is complete, but the replacement comes from another manufacturer. Accepting an alternative manufacturer is a technical decision for engineering; the materials review prepares it.

  6. IfBOM and master data: Not addressed

    Professional positionReplacement supported

    ConditionalClarification required

    Any other decision: not supported by the signals

    OEM supersession, manufacturer data and documentation support the replacement technically. The change is not finished: until the BOM and the material master are updated, planners still find the old item through the equipment, and its stock may be reordered.

  7. IfAny other combination

    Professional positionReplacement supported

    Any other decision: not supported by the signals

    OEM supersession, manufacturer data and documentation support the replacement.

Illustrative scenario. The lab shows the materials review; technical acceptance of a replacement remains with engineering.

12Connected intelligence

Experience

See this principle in practice

Decision Lab

Apply the decision logic

13Evidence and basis

The example is illustrative, not a record of a specific company item. Basis: slow-moving and obsolete stock reviews, technical evaluations and material-to-equipment data work across the CV roles. Technical acceptance of alternatives is described as an engineering decision, not as the author's authority.

Obsolescence Slow-moving stock Alternatives

Published 1 Oct 2026

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