Managing Drawing Revisions for Medical Sheet Metal Assemblies

A supplier can manufacture exactly what it receives and still deliver the wrong configuration if the RFQ contains conflicting revisions. A new STEP model, an old PDF and a purchase order copied from last month do not form a controlled instruction.

Revision control is the connection between design intent, physical parts and the commercial order. It should remain clear from the initial quotation through repeat delivery.

Release one coherent package

Identify the governing documents and their revisions. Include the assembly BOM, component drawings, model files and referenced specifications. State the agreed precedence or resolution process where information conflicts; do not expect the shop to guess.

Document	Control question
Assembly BOM	Which component revisions form the ordered configuration?
Component drawing	Are dimensions, material, finish and inspection notes current?
CAD model	Does it match the released drawing and interface?
Purchase order	Does it reference the intended configuration and deliverables?
Approved deviation	What scope and expiry or effective boundary apply?

Use filenames and delivery records that make the package identifiable, but do not rely on filenames alone as approval evidence.

Separate revision from interchangeability

A revision tells the record has changed. It does not automatically explain whether old and new parts can be mixed. The responsible design authority should define interchangeability and the effective change boundary.

For example, a connector opening change may require a new mating panel even when the outer dimensions remain identical. A note correction may have no physical effect. Both are changes, but their production dispositions differ.

Confirm receipt before starting work

Ask the supplier to acknowledge the released package and flag discrepancies. The acknowledgment should identify the relevant revision set and exceptions, not merely confirm that an email arrived.

If a revised file is sent during manufacture, use a formal change instruction. The supplier needs to know whether to stop, continue the old order, segregate work or wait for a defined effective point.

Control the pilot-to-repeat transition

Pilot approval should identify the configuration actually evaluated, including any temporary changes or customer-supplied hardware. Determine which exceptions are closed, which are permanent design changes and which apply only to the pilot.

Before a repeat order, reconcile the approved pilot record with the current drawing, BOM and purchase order. Do not reproduce an undocumented hand modification simply because it made the pilot fit.

Use the first-article fit-up checklist to keep physical verification linked to document identity.

Preserve identity through storage and replacement

Parts can lose their revision identity when they leave their packaging or enter shared bins. Define direct marking, identified packaging or another controlled method appropriate to the component.

Replacement parts deserve the same attention as complete kits. A service cover shipped months later must match the intended installed configuration, or an approved replacement relationship must be supplied.

Close obsolete work with an authorized disposition

When a change affects existing parts, record whether they may be used, reworked, returned or otherwise dispositioned under the agreement. Do not let obsolete stock remain indistinguishable from released stock.

The engineering change cost review explains why production stage and affected quantity belong in this conversation. Configuration control and commercial disposition need to describe the same physical material.

RFQ and reorder handoff

Provide a revision register, a complete document package, the approved deviation list, identification requirements and the authority for changes. Request the same configuration references in the agreed delivery records.

DRAmetal can review medical component kits, housing components and medical chassis against that package. A repeat order should reproduce an approved configuration, not an informal memory of the last shipment.