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5.6 Kitting, FIFO & Shortage Management

Kitting is the discipline that keeps a factory floor flowing—matchingflowing, ensuring the exact right parts tofrom the exact right buildtraceable withoutlots guesswork,arrive drama,at orthe lateexact scrambles.right time. By lockinglinking eachevery kit to a frozen BOM/AVL snapshot, traceable lots, and FIFO/FEFO issuing, the risk of “mystery reels” or expired paste vanishes. Line-side supermarkets stay calm through shelf discipline and simple min/max rules, while MSDs are protected until the very moment they’re loaded.

When shortages do hit, structured triage (DNS vs. BT) prevents WIP piles and keeps escalation visible. Substitutions are handled through controlled deviations, never “looks close enough.” And at the end of each run, clean count-backs and resealing ensure the next kit starts with a clear slate.

5.6.1 Purpose & scope

Turn a BOM into the right parts, right lots, right place, right time—without starving the line or growing mystery bins. This covers kit creation, supermarket control, FIFO/FEFO rules, substitutions/deviations, shortage triage,snapshot and adhering to strict inventory rules, kitting transforms material logistics from a scramble into a reliable choreography.

5.6.1 The Perfect Kit: Traceability and Accuracy

A controlled kit is not a pile of parts; it is a traceable package locked to a specific product definition. kitAccuracy close-outbeats speed forduring PCA,the THTpicking add-ons, and box-build.process.



5.6.2

Kit fundamentals (how a good kit looks)

Fundamentals

  • Locked to a snapshot:Snapshot: KitEvery tieskit must be tied to a BOM/AVL + revision that was current at pickthe time;time ECNsof afterpicking. pickAny triggerEngineering Change Notice (ECN) issued afterward triggers a kit review/freeze.
  • TraceableTraceability lots:Mandate: EachEvery line item hasmust have a UIDUnique +ID lot/date(UID), linking it to the specific Lot/Date code; nologged “loose”at handfuls.receiving (5.1). No "loose" or unlabeled handfuls are permitted.
  • OneMSD lotand perESD feederControl: (preferred).Sensitive Ifmaterials mixingmust lotsmaintain fortheir passiveschain isof allowed, one lot per position and log both lots in MES.
  • MSDs controlled:custody. MSD reels/traysreels stay sealed or in a DRY-CAB until load (5.4). Don’tuntil stagethe MSDmoment kitsof early.
  • ESD right:loading. All parts travel in shielding totes/bags with UID visible (5.3).

Issuing Rules: FIFO vs. FEFO

The choice of inventory method depends on the material's shelf life risk:

  • ChemistriesFIFO separate:(First In, First Out): Paste/fluxUsed arefor notstandard components, PCBs, and hardware. Use the oldest received material first, unless an engineering request dictates otherwise.
  • FEFO (First Expiry, First Out): insideUsed kits; issued byfor FEFOchemistries (paste, flux, adhesives). andIssue trackedthe perlot that expires soonest, ensuring enough life remains for the planned run (5.5.
    5).


Picking
Protocol


The process must be system-driven to ensure accuracy:

5.6.3 Picking rules (accuracy beats speed)

  1. Verify the& order:Scan: WO, variant, rev, quantity, due date.
  2. Scan tothe pick:Work Order (WO), then scan the UID of every item picked. Every UID is scanned;The MES validatesmust validate the PN ↔– locationLocation ↔– lotLot and warnsflag onincorrect wrong revrevisions or off-AVL.AVL parts.
  3. FIFO for parts / FEFO for chemistries:
    • Components, PCBs, hardware → FIFO by received date (unless engineering requests a specific lot).
    • Paste/flux/adhesives → FEFO (5.5).
  5. Count and& confirm:Record: Use scales/scales or counters forto reels/tubes;verify recordquantity. Record the issued qtyquantity and the expected remainder.
  6. LabelFinal the kit:Label: KitThe completed kit card lists the WO, variant, rev,revision, and all UIDs,UIDs, MSDserving status,as the final inventory manifest.

5.6.2 Crisis Control: Shortages and staging location (LINE-SMKT shelf/bin).
Deviations

AccuracyWhen target:the ≥99.8%materials lineplan itemsfails, right,structured triage prevents a crisis from turning into a warehouse full of unproductive 0Work In Process (WIP).

wrong

Shortage PNTriage (DNS vs. BT)

Shortages must be classified to line.determine the right action:



5.6.4 Line-side supermarkets (calm, not crowded)

  • Min/Max: For high-runners, set min–max by usage/takt; kanban two-bin works well for screws, labels, and fixtures.
  • Shelf discipline: One PN per slot, lot tags face out; no gray bins or “misc” shelves.
  • Color & zone: Color code by product family/variant; post a simple map on the endcap.
  • Aging control: If a kit sits >24–48 h unstarted, return MSDs to DRY-CAB or resealDNS (5.4) and re-validate before release.



5.6.5 Substitutions & deviations (no “close enough”)

  • Use AVL first. If an alternate is on the AVL, MES should accept it automatically.
  • Not on AVL? Raise a Deviation/Waiver with PE/QE sign-off (and Design if electrical). Check: form/fit/function, derating, test limits, labels, and compliance (RoHS/REACH).
  • Document the decision: Ticket ID on the kit card; tag feeders loaded with deviated parts; ensure test recipes don’t mis-bin the change.
  • Close the loop: If deviation becomes permanent, push an ECN and update AVL/BOM.



5.6.6 Shortage management (avoid starving the line)

  • Do-Not-Start (DNS)Start): If critical items are missing (ICs, bare boards, unique connectors), are missing, DNS the WO. Don’tDo not start partialsa partial build that will immediately starve the line or clog WIP.the WIP area.
    • Triage A (Critical): Unique IC, PCB, high-value module – DNS.
  • BT (Build-through list:Through): If only non-blocking items (standard hardware, labels, shields) are missing (screws, shields),missing, you may BT with QE/MEProduction/Engineering approvalsign-off and a clean re-touch plan.
  • Visual board: Maintain a Shortage Board (digital/physical) showing WO, PN, qty missing, ETA, owner, escalation level.
  • Hot lots: Mark expedited receipts with a HOT tag tied tofor the shortagemissing ticket; route straight to parts.LINE-SMKT.

  • Triage categories

    • A (Critical): Unique IC, PCB, high-value module → DNS.
    • B (Conditional): Mechanical/hardware that can be installed later →– BT with plan.
    • C (Cosmetic/pack): Labels, manuals → may ship hold; coordinate with 26.3.


Maintain a Shortage Board (digital or physical) showing WO, PN, quantity missing, ETA, and owner for clear, continuous escalation.

Substitutions and Waivers


The rule is clear: No "close enough."

  • If an alternate part is needed and is 5.6.7Not Loading & consumption (clean hand-off toon the machines)AVL

,
  • a formal Scan to load:Deviation/Waiver Feedersis onlymandatory. acceptThis UIDsrequires sign-off from Process/Quality Engineering (PE/QE) and potentially Design.
  • The waiver must confirm form, fit, function, test limits, and compliance. Document the decision on the kit card;card MESand tiesensure machine UIDtest ↔recipes feederare ↔ programupdated. before loading the deviated part.

5.6.3 Line-Side Management and Reconciliation

The line-side supermarket must be calm, not crowded. Clean close-out is mandatory for maintaining inventory accuracy.

Supermarket Discipline

  • Min/Max: Use Min/Max levels tied to usage rates (takt time) or Kanban two-bin systems for high-volume consumables.
  • Backflush/consume:Shelf Standard: As placement proceeds, consumption decrements byEnforce verifiedone partPN countper slot. Ensure lot tags face outward, and no gray bins or unlabeled "misc" storage is allowed.
  • Aging Control: If a staged kit sits > 24 – 48 hours unstarted, MSDs must be returned to DRY-CAB or resealed (machine5.4), countand orthe scale).entire kit must be re-validated before release.
  • ReelLoad splits & splicing:Scan: WhenThe splicing, label new tail with themachine samemust scan the UID plusto -A/-B suffix; scantie the splice.specific NoLot/Serial nakedto tailthe pieces.program.


Kit
Close-Out


At

5.6.8the Returnsend &of reconciliationthe (closerun, the kit cleanly)

must
    be closed cleanly:

    1. End of run:Count-Back: Count back reels/tubes/trays;and scan backremaining reels/trays/tubes to stock;update updatethe quantity remaining qty.in the MES.
    2. MSDs:MSD Management: Reseal any opened MSDs with fresh HIC/desiccant or park the reels in the DRY-CAB;. updateUpdate the floor-life timer perin the system (5.4.4).
    3. Scrap jars/tubesScrap: Scrap all chemistries (paste/flux) that have violated their open-time/time or expiry rules (5.5).
    4. Variance ticket:Variance: Any mismatch opensbetween the MES expected remainder and the scanned count-back requires a ticket;Variance recount once; if still off, QE investigates (lot split, feeder loss, or pick error).



5.6.9 Metrics that keep you honest

  • Kitting accuracy (%)Ticket =for right line items / total line items.investigation.
  • On-time kits

    5.6.4 (%) to requested start.

  • Shortages per WOOversight and DNSEfficiency hoursMetrics (lost

    Managers time).

  • Supermarketdrive servicestability levelby (%)measuring (stockoutsthe vs demand).
  • Kit age (days) from pick to start.
  • Substitution rate (%)process and deviation lead time.

Review weekly; fixtargeting the biggestlargest painsource of inefficiency first.



5.6.10 Acceptance cues (fast table)

CheckpointMetric

Accept

RejectFocus

KitKitting cardAccuracy (%)

WO/variant/revRight +line allitems UIDs/ present

HandwrittenTotal notes;line missingitems lots(Target: ≥ 99.8%)

FIFO/FEFO

ComponentsDNS by FIFO; chemistries by FEFOHours

“NewestLost first”;production expiredhours mid-rundue to critical shortages (Target: 0)

MSDKit controlAge (days)

ReelsTime sealedfrom orkit inpick DRY-CABto untilstart load

MSDsof stagedproduction open(Shorter overnightis better for risk control)

ShelfSupermarket disciplineService Level (%)

OneStockouts PNvs. perDemand slot;(Reflects labelsKanban/Min-Max out; no gray bins

Mixed PNs; unlabeled cupshealth)

SubstitutionsSubstitution Rate (%)

AVLRatio orof approvedbuilds deviationusing attached

“Looksnon-BOM, same”waived swap with no record

Returns

Count-back scanned; MSDs resealed/parked

Loose remainders; no timer updateparts


Common
Traps – Smallest Reliable Fix


5.6.11 Common traps → smallest reliable fix

Trap

Symptom

First moveMove (The Reliable Fix)

Early kittingKitting of MSDs

HIC wet, floor-life timer wasted before start.

Pick MSDs closest to start time; userely on DRY-CAB stagingstaging.

Partial start on critical shortage

WIP pile, rework later

DNS until criticals arrive; BT only with plan

Lot mixingMixing in one feederFeeder

Traceability headacheis broken; hard to isolate defects.

One lot per feeder;feeder; if mixed passives allowed, log both

Decanting without labels

“Mystery bin” finds

No decanting; if required, print child UIDlots referencingto parentthe position.

Paste insideInside kitsKits

ExpiredChemistry expires/condenses on arrival at the line.

Issue chemistries separately by FEFO; never stage them with components.

Partial Start on Shortage

UnplannedWIP substitutionspile, line clog, cost increase.

DNSAOI/test falsefor failscritical shortages;

BTDeviation +only with a firm re-touch and test library update before loadplan.



5.6.12 Pocket checklists

Before picking

  • WO/variant/rev confirmed; AVL current
  • MSDs planned to pick near start time

During pick

  • Scan every UID; FIFO/FEFO observed
  • Kit card printed; shielding totes; MSDs sealed

At line release

  • Substitutions/devs attached; feeders labeled
  • MSD floor-life sufficient for shift + buffer

Close-out

  • Count-back scanned; MSDs resealed/DRY-CAB
  • Variance ticket opened if counts don’t match



Do all that, and kitting fades into the background—a quiet, reliable choreography that lets the line run smooth, parts stay traceable, and no one discovers a problem halfway through the build.


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