Material Substitution Approval: Request, Review and Release

A proposed material substitute should stay on hold until the responsible technical authority approves its use for a defined product, quantity and scope. Record the requested alternative, the requirement it would replace, the evidence reviewed and the decision before stores issues it to production.

This workflow is for purchase, engineering, quality and stores when the specified material is unavailable or a supplier offers an alternative. The task is to control the decision. A similar description, lower price or supplier assurance does not establish technical equivalence.

Open a request against the affected requirement

Purchase records the order, item, current specification and revision, required quantity, delivery constraint and proposed substitute. Attach the supplier's technical information with its version and source. Keep the original requirement visible; do not edit the item description to make the incoming material appear compliant.

NASA's configuration-management guidance describes proposing, evaluating, approving and verifying changes. It also distinguishes an authorized waiver from a baseline change. The request below uses that decision discipline without asserting a material equivalence or a certification.

Give reviewers a decision sheet

The table deliberately contains no recommended material grade. Only the authorized technical review can decide suitability for the actual application. If the evidence is incomplete, record the missing input and keep the request pending.

Keep temporary permission bounded

In an illustrative case, a job needs 80 blanks. The reviewer approves substitute item S-2 for 30 named blanks on that order while the original 50 are supplied as specified. Stores must issue the two materials under their actual identities, with the approval reference attached to the 30 substitute blanks.

If 40 substitute blanks were purchased, the remaining ten are not automatically approved for another order. Record their location and restricted status until a new decision covers their use. The arithmetic is simple; preserving the boundary during the next urgent request is the control.

A permanent change requires the applicable master-data, BOM, drawing and process changes. A one-order permission must not silently alter those standards. Keep the prior approved records available for the orders that used them.

Trace the decision into issue and inspection

Engineering records the technical decision and any revised processing instruction. Quality defines the acceptance evidence and any additional checks. Purchase updates the supplier instruction. Stores confirms the material identity and permitted quantity before issue. Production uses the approved route and retains the link to the authorization.

Use the BOM guide when the decision changes the standard material requirement. A production shortage should not be “fixed” by merging two item codes or relabelling an unapproved lot.

If an unapproved substitute has already been issued, record the actual material and affected jobs, segregate remaining stock and route the affected work for quality and engineering review. Backdating an approval would erase the sequence needed to understand the event.

Test the boundary before adopting the workflow

Try four records in a controlled pilot: a complete request, a request missing technical evidence, an issue within the approved quantity and an attempted issue beyond it. Check that the responsible people can identify the decision and remaining permitted quantity in each case.

Acceptance means every issued substitute can be traced to an applicable approval, the issued amount stays within its scope, unfinished reviews remain visible and leftover material has an owner. Review expired permissions and recurring substitutions; repeated emergency requests may justify a formal sourcing or design review.

Configure the request in Optiwise

With Optiwise no-code modules, we can configure a substitution-request record with related orders, attachments, mandatory fields, role access and notifications. Connect it to material issue and quality checks so the approved conditions travel with the work.

This is a configurable approval workflow. Our software records and routes the decision; it does not certify that two materials are technically interchangeable. Keep the authorized technical reviewer responsible for that conclusion.

Questions about material substitution

Can purchase approve an alternative because the supplier calls it equivalent?

Purchase can submit the proposal and evidence. The authorized technical and quality reviewers, plus any required customer authority, decide whether it is acceptable for the defined use.

Does a temporary approval change the BOM?

Not automatically. Keep temporary permission tied to its order, lot or quantity. A permanent baseline change follows the applicable engineering and master-data release process.

Bring one redacted substitution request to a demo and we can map its evidence, approval scope and issue checks in Optiwise.