5.6 Kitting, FIFO & Shortage Management
Kitting is the discipline that keeps a factory floor flowing—matching the exact right parts to the exact right build without guesswork, drama, or late scrambles. By locking each 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, and kit close-out for PCA, THT add-ons, and box-build.
5.6.2 Kit fundamentals (how a good kit looks)
- Locked to a snapshot: Kit ties to BOM/AVL + revision at pick time; ECNs after pick trigger kit review/freeze.
- Traceable lots: Each line item has UID + lot/date code; no “loose” handfuls.
- One lot per feeder (preferred). If mixing lots for passives is allowed, one lot per position and log both lots in MES.
- MSDs controlled: MSD reels/trays stay sealed or in DRY-CAB until load (5.4). Don’t stage MSD kits early.
- ESD right: All parts travel in shielding totes/bags with UID visible (5.3).
- Chemistries separate: Paste/flux are not inside kits; issued by FEFO and tracked per 5.5.
5.6.3 Picking rules (accuracy beats speed)
- Verify the order: WO, variant, rev, quantity, due date.
- Scan to pick: Every UID is scanned; MES validates PN ↔ location ↔ lot and warns on wrong rev or off-AVL.
- 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).
- Count and confirm: Use scales/counters for reels/tubes; record issued qty and expected remainder.
- Label the kit: Kit card lists WO, variant, rev, all UIDs, MSD status, and staging location (LINE-SMKT shelf/bin).
Accuracy target: ≥99.8% line items right, 0 wrong PN to line.
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 reseal (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): If critical items are missing (ICs, boards, unique connectors), DNS the WO. Don’t start partials that will clog WIP.
- Build-through list: If only non-blocking items are missing (screws, shields), you may BT with QE/ME approval 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 to the shortage ticket; route straight to 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.
5.6.7 Loading & consumption (clean hand-off to the machines)
- Scan to load: Feeders only accept UIDs on the kit card; MES ties UID ↔ feeder ↔ program.
- Backflush/consume: As placement proceeds, consumption decrements by verified part count (machine count or scale).
- Reel splits & splicing: When splicing, label new tail with the same UID plus -A/-B suffix; scan the splice. No naked tail pieces.
5.6.8 Returns & reconciliation (close the kit cleanly)
- End of run: Count back reels/tubes/trays; scan back to stock; update remaining qty.
- MSDs: Reseal with fresh HIC/desiccant or park in DRY-CAB; update floor-life per 5.4.
- Scrap jars/tubes that violated open-time/expiry rules (5.5).
- Variance ticket: Any mismatch opens a ticket; recount once; if still off, QE investigates (lot split, feeder loss, or pick error).
5.6.9 Metrics that keep you honest
- Kitting accuracy (%) = right line items / total line items.
- On-time kits (%) to requested start.
- Shortages per WO and DNS hours (lost time).
- Supermarket service level (%) (stockouts vs demand).
- Kit age (days) from pick to start.
- Substitution rate (%) and deviation lead time.
Review weekly; fix the biggest pain first.
5.6.10 Acceptance cues (fast table)
5.6.11 Common traps → smallest reliable fix
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