Your parts failed first-article inspection, and now the project is paused while everyone waits for a decision on what to do next.
When an FAI fails, the next step is to determine whether the failure proves a supplier capability limit, a reworkable manufacturing error, or a drawing requirement that already prevents compliance. That classification directly determines whether the parts can be reworked, the first article must be restarted, or the supplier must be replaced. Proceeding without this decision almost guarantees another failure.
The sections below walk through how to classify FAI failures correctly, how to tell scrap from salvage, and how to decide—with evidence—whether continuing with the same supplier will ever produce a stable, repeatable result.
Table of Contents
Which FAI failures show your supplier can’t make the part?
A part cannot be made by the current supplier when the same critical features fail FAI more than once despite setup changes or rework. This indicates a process capability limit, not a correctable manufacturing error.
These failures show up as repeated out-of-tolerance results on the same features, geometry that shifts between setups, or dimensions that only approach spec when tolerances are informally relaxed. In all cases, the supplier is operating outside a stable production window and cannot demonstrate repeatability.
At this point, another first-article attempt rarely changes the outcome. When a supplier proposes offsets, “fine tuning,” or one more trial without showing controlled process data, the risk moves downstream. Even if a second FAI passes, production drift and lot-to-lot variation become likely.
Production-capable shops either demonstrate control during first article or identify the limitation early. When capability gaps surface only after inspection, it usually means the supplier accepted work beyond their true limits.
Decision Takeaway:
If the same critical features fail FAI more than once or vary across setups, treat it as a supplier capability failure—not a tuning issue. Continuing with the same supplier risks repeat failure in production
Is this FAI failure caused by your drawing—or the supplier’s machining process?
An FAI failure is drawing-caused when the same feature fails the same way every time, and process-caused when results vary between setups or operations. This distinction determines whether redesign is required—or whether the supplier must be changed.
Drawing-driven failures are consistent and predictable. They result from conflicting GD&T, impossible tolerance stacks, or inspection requirements that block compliance. These failures repeat identically regardless of machine, setup, or operator, and no supplier can pass FAI without clarifying or modifying the requirement.
Process-driven failures behave differently. Measurements drift, features move after finishing, or parts pass before secondary operations and fail afterward. These patterns point to tool deflection, thermal effects, sequencing errors, or missing in-process inspection—not drawing defects.
Redesigning in response to variable failures rarely fixes the problem. It simply hides process instability and pushes risk into production.
Decision Takeaway:
If the failure is consistent, review the drawing. If the failure is variable, stop and reassess supplier process capability before approving redesign or another FAI attempt.
Which failed features already make your FAI parts scrap versus salvageable?
FAI parts are scrap when failed features affect functional geometry, safety-critical interfaces, or finished dimensions that cannot be reworked without altering form, fit, or performance. Cosmetic defects or oversize conditions before finishing may be salvageable; undersize, distorted, or post-process failures usually are not.
Scrap-level failures include undersized holes or shafts, distorted flatness after stress relief, mislocated features that break positional tolerance, and any failure on hardened, coated, or finished surfaces where material removal is no longer possible. These failures permanently violate the drawing and cannot be corrected without re-machining the part.
Salvageable failures tend to be early-stage issues: excess stock left on critical faces, unfinished features that missed tolerance before final machining, or surface finish failures prior to coating. In these cases, controlled rework may be possible if sufficient material remains and geometry has not shifted.
The danger is approving rework without confirming which category the failure falls into. Reworking scrap-level failures often consumes time and cost while producing parts that still fail final inspection or assembly.
Decision Takeaway:
If a failed feature cannot be corrected without changing finished geometry or functional interfaces, treat the part as scrap. Only approve rework when the failure is dimensional, correctable, and occurs before irreversible processes.
Is This FAI Failure Fixable—or Not?
Upload your drawing and FAI results to confirm whether these parts can be salvaged or must be restarted
Which drawing requirements are blocking any FAI rework on the current parts?
FAI rework is blocked when drawing requirements cannot be met without adding material, reversing finished operations, or violating functional geometry. In these cases, no amount of machining adjustment can bring the part into compliance.
Common blockers include minimum material conditions already exceeded, tight positional tolerances tied to datums that have shifted, surface finish requirements applied after coating, and GD&T callouts that assume an operation sequence the supplier did not follow. Once these conditions exist, rework becomes mathematically impossible.
Suppliers may still propose rework by selectively ignoring inspection criteria or re-measuring from alternate datums. That approach does not fix the part—it only masks nonconformance and shifts risk to assembly or field failure.
A proper evaluation checks whether any rework path exists within the original drawing intent. If compliance requires reinterpretation, waiver requests, or undocumented deviations, the drawing itself has already blocked recovery for the current parts.
Decision Takeaway:
If meeting the drawing requires adding material, undoing finished operations, or redefining datums, rework is not viable. At that point, restart or supplier change is the only path that restores compliance.
Did the FAI failure occur because the supplier cannot hold your tolerances?
An FAI failure indicates tolerance capability limits when measured values cluster near or beyond limits with no stable center across setups or operations. This pattern signals insufficient process control, not bad luck.
Tolerance-driven failures often show tight dimensions passing once, then drifting after tool changes, finishing, or part removal. Measurements may appear acceptable in isolation but fail when repeated or inspected at different stages. This behavior points to machine rigidity limits, thermal instability, or missing in-process inspection—not drawing errors.
When suppliers cannot demonstrate consistent results around nominal values, they typically request tolerance relaxation after FAI. That request is not proof the tolerance is unreasonable; it is evidence the supplier cannot reliably hold it.
Approving tolerance changes under this pressure hides the real issue. Even relaxed tolerances may drift further in production, creating downstream quality and assembly problems.
Decision Takeaway:
If FAI measurements do not repeat tightly around nominal values, assume a tolerance capability issue. Before relaxing specifications, determine whether the supplier can ever demonstrate stable control at production scale.
Which finishing or post-processing steps caused your FAI rejection?
FAI failures caused by finishing or post-processing occur when dimensional change, surface damage, or tolerance loss appears only after coating, heat treatment, or secondary operations. These failures point to post-process control gaps, not machining errors alone.
Common examples include threaded features going out of tolerance after anodizing, flatness loss after heat treatment, coating thickness pushing parts beyond size limits, or surface finish degradation during secondary handling. In each case, the part passed earlier stages and failed only after a downstream process.
This pattern matters because finishing steps amplify small upstream variations. Suppliers without controlled allowances, masking strategy, or post-process inspection treat finishing as cosmetic rather than dimensional. Re-running FAI without changing post-process control almost always reproduces the failure.
A production-capable supplier can show documented coating allowances, dimensional compensation strategy, and post-process inspection results before approving another FAI. If those controls cannot be shown up front, finishing-related FAI failures will persist.
Decision Takeaway:
If the part passed before finishing and failed after, require the supplier to show how finishing effects are predicted, measured, and compensated before approving another FAI. If they cannot demonstrate this immediately, switching suppliers is lower risk than retrying.
Did material behavior or heat treatment distortion cause these FAI parts to fail?
FAI failures caused by material behavior appear when parts move, warp, or change dimension after machining due to residual stress, heat treatment, or material condition. These failures are systemic, not incidental.
Typical signs include flatness or straightness loss after stress relief, bore distortion after hardening, or size change following thermal cycles. These effects cannot be corrected with offsets; they require process planning that anticipates material movement.
Suppliers who machine to final size before heat treatment or skip intermediate stress relief often trigger repeat FAI failures. Once distortion occurs, rework options are limited, especially on tight-tolerance or finished features.
A production-capable supplier can show revised operation sequencing, controlled stock allowance before heat treatment, and post-HT dimensional verification data prior to the next FAI. Without this evidence, another attempt is likely to fail the same way.
Decision Takeaway:
If dimensions were correct before heat treatment and failed afterward, do not approve another FAI until the supplier presents a revised sequence that explicitly controls distortion. If no revised process is provided, assume repeat failure risk.
When does an FAI failure signal the supplier cannot meet production repeatability?
An FAI failure signals lack of production repeatability when results cannot be reproduced consistently across setups, operators, or inspection stages. This indicates an unstable production process.
Warning signs include measurements that pass once and fail later, inconsistent results between parts in the same run, or dependence on a specific setup or operator to meet tolerance. A single passing FAI under ideal conditions does not prove repeatability.
Suppliers may still achieve a passing first article by tightening oversight or manual intervention. That success does not scale. Without controlled inputs and in-process verification, variation will exceed limits during production.
A production-capable supplier can show repeat measurements, in-process inspection checkpoints, and consistency across multiple parts within the FAI window—not just one conforming sample.
Decision Takeaway:
If FAI success depends on perfect conditions or manual tuning, treat it as non-repeatable. Require evidence of consistency across multiple measurements before approving production or continuing with the supplier.
How quickly can the supplier deliver a passing first article after this failure?
After an FAI failure, a realistic passing first-article timeline depends on whether the supplier can correct the root cause without changing the process scope. If the fix requires new tooling, resequencing, or external processing changes, timelines extend quickly.
Minor, isolated errors—such as missing offsets or incomplete operations—can often be corrected within days. However, failures tied to tolerance capability, finishing control, or material behavior typically require process redesign, new validation, and another full inspection cycle. In those cases, fast promises usually reflect optimism, not readiness.
A reliable recovery timeline is based on what the supplier can demonstrate immediately. If they cannot show a revised process plan, inspection checkpoints, and confirmation of corrective actions within a short window, the stated delivery date is speculative.
Suppliers who respond with vague timing (“next week,” “soon”) or conditional language (“if everything goes well”) are signaling uncertainty. At this stage, speed without clarity increases risk rather than reducing it.
Decision Takeaway:
If the supplier cannot present a concrete recovery plan and revised FAI schedule within a defined timeframe, assume delays will continue. When time matters, choosing a supplier that can assess and quote a recovery path immediately is safer than waiting on uncertain retries.
Should you rework the current parts, restart production, or switch to a new supplier?
You should rework parts only when failures are isolated and correctable, restart when the process is sound but execution failed, and switch suppliers when the failure exposes a capability or repeatability gap. Choosing the wrong path compounds cost and delay.
Rework makes sense when material remains, geometry is intact, and compliance can be restored without redefining requirements. Restarting production is justified when the root cause is known, corrected, and verified—but the existing parts cannot be recovered.
Switching suppliers becomes the lowest-risk option when failures repeat, corrective actions lack evidence, or confidence in production stability is lost. Continuing in those conditions often turns a single FAI failure into a multi-cycle delay.
The decision should be based on evidence, not sunk cost. Time already spent does not reduce future risk.
Decision Takeaway:
If the failure reflects unstable capability or unclear corrective action, switching suppliers is usually faster and safer than repeated retries. Make the decision based on forward risk, not past investment.
Rework, Restart, or Switch Suppliers?
Share your part details to assess recovery speed, repeatability risk, or remanufacture timelines
What evidence must a supplier show before you trust the next FAI attempt?
Before approving another FAI attempt, the supplier must show evidence that the failure cause is understood, corrected, and controlled—not just adjusted. Without proof, another attempt is only a guess.
At minimum, this evidence includes a revised process plan, defined inspection checkpoints, and confirmation of how variation is controlled at the failure point. For tolerance or post-process issues, measurement data must show repeatability—not a single corrected result.
Promises, screenshots, or verbal explanations are not substitutes for documented control. If the supplier cannot produce objective evidence quickly, confidence should drop—not increase.
Trust at this stage is earned through visibility and verification, not reassurance.
Decision Takeaway:
Do not approve another FAI based on intent alone. Require documented corrective actions and measurable control before committing time or material to another attempt.
What drawing details explain why the current FAI already failed?
FAI failures tied to drawing details usually stem from requirements that block compliance through tolerance stacking, datum definition, or post-process constraints. These issues are structural and will repeat until clarified.
Indicators include features tied to shifting datums, tight positional tolerances applied after finishing, or specifications that assume an operation sequence that was not defined. In these cases, even capable suppliers may struggle unless the requirement is interpreted or staged correctly.
The key is separating drawing limitations from execution failures. If the failure can be predicted directly from the drawing, redesign or clarification may be required. If not, the issue lies in how the part was made or inspected.
Changing suppliers without understanding this distinction risks repeating the same failure elsewhere.
Decision Takeaway:
If the drawing itself prevents compliance, address it before restarting or switching. If the failure cannot be explained by the drawing alone, focus on supplier capability and process control instead.
Conclusion
FAI failures are rarely random—they reveal capability limits, process gaps, or blocked requirements. The costliest mistake is retrying without evidence. If your first article failed and timelines matter, upload your drawing and inspection report for a second-opinion assessment and recovery plan within 24 hours.
Frequently Asked Questions
Only if the supplier can show documented corrective actions and measurable process control. If the next FAI relies on “adjustments” without evidence of repeatability, approving another attempt usually leads to the same failure and more delay.
Require a revised process plan, defined inspection checkpoints, and evidence of control at the failure point. Verbal assurances or screenshots are not proof. Without documented corrective action, another FAI is a risk, not a solution.
If the same feature fails the same way every time, the drawing may block compliance. If results vary between setups or operations, the issue is usually supplier process control. This distinction should be confirmed before redesign or supplier switching.
Switch suppliers when failures repeat, timelines are unclear, or corrective actions lack evidence. At that point, continuing usually increases risk. Uploading drawings for a second-opinion assessment is often the fastest way to regain control.
Rework is cheaper only when failures are isolated and fully correctable. When failures expose capability or repeatability gaps, restarting—or switching suppliers—is often faster and less costly than repeated rework and failed attempts.
A capable supplier can assess drawings and inspection data within 24 hours and provide a recovery plan and timeline quickly. If a supplier cannot define the path forward immediately, recovery timelines are speculative rather than reliable.
