Why Is a Stocking Strategy Critical?
- THE COST OF A STOPPAGE — lost hourly revenue plus fixed overheads
- LEAD TIME — a spare part from outside Türkiye can take 2-6 weeks to arrive
- A CRITICAL PART — without it the machine stops altogether
- A CONSUMABLE PART — replaced periodically (orifice, focusing tube, blade)
- AN INSURANCE PART — rarely needed, but a large loss when it is missing
ABC Analysis — Setting Priorities
Not every part matters equally; ABC analysis divides parts into 3 classes:
| Class | Definition | Stocking Strategy | Examples |
|---|---|---|---|
| A — Critical | Its absence stops production; long lead time | Always in stock, minimum 1-2 off | Pump seal, valve, control board |
| B — Consumable | Periodic replacement, can be planned | Monthly consumption × 2 in stock | Orifice, blade, garnet |
| C — General | Common, quick to source | Just-in-time or minimal | Bolts, seals, cable |
Waterjet — The Critical Spare Parts List
- A: UHP pump seal kit — minimum 2 kits
- A: Pump valve kit — minimum 1 kit
- A: A spare CNC control board (for a machine 5+ years old)
- B: Diamond/sapphire orifice — monthly consumption × 2
- B: Focusing tube — monthly consumption × 2
- B: Mixing chamber — monthly consumption × 1
- B: High-pressure hose — 1 spare set
- C: General bolts, seals, cable — minimal
CNC Bridge Saw — The Critical Spare Parts List
- A: Spindle oil filter — 2 spares
- A: A spare CNC control board
- A: Servo motor (1 spare for the most critical axis)
- A: A set of limit switches
- B: Diamond blade — weekly consumption × 4
- B: Spindle tool holder (ER25/HSK63) — 2-3 spares
- B: Lubricating oil — monthly consumption × 3
- B: Vacuum table seal
- C: General consumables
Sandblasting — The Critical Spare Parts List
- A: Gun safety trigger (deadman) kit
- A: Pressure regulator
- A: Pressure gauge
- B: Nozzle (abrasive plus air) — monthly consumption × 3
- B: Hose (air plus abrasive) — 1 spare set
- B: Tank seal
- C: Filters, valves, seals — monthly consumption × 2
Stock Management Systems
The Min-Max System (Classic)
- A "minimum" and a "maximum" stock level are set for each part
- An order is triggered when stock falls below the minimum level
- The order quantity equals the difference between maximum and minimum
- Advantage: simple, and manual tracking is possible
- Disadvantage: slow to respond to a change in the consumption trend
JIT (Just-in-Time)
- Stock is kept to a minimum and the part is ordered at the moment of need
- Advantage: low stockholding cost, no risk of stock going out of date
- Disadvantage: a delay in supply → a production stoppage
- Only for parts with a short lead time (locally sourced spares)
- NEVER JIT for a critical part — a minimum stock is essential
Consignment Stock
- The supplier holds its stock at the workshop and invoices once it is used
- The workshop invests nothing in stock
- Possible where the supplier is large and the customer is a continuing one
- Authorised service providers such as USEL may offer it to a large customer
Service Agreement (SLA)
Instead of holding spare parts yourself, or alongside doing so — enter into an SLA with the authorised service provider:
- An annual fixed fee plus stock management by the service provider
- A guaranteed lead time (24-48 hours is typical)
- Periodic maintenance included — an annual service visit
- Telephone support 24/7
- Remote diagnostics (TeamViewer/USB log analysis)
- For the workshop: less capital tied up in stock plus expert support
- USEL Authorised Service offers an SLA option — the detail is on the /en/service page
Stock Management Software
- PLAIN EXCEL — enough for a small workshop
- AN ERP MODULE (SAP, Microsoft Dynamics) — a medium to large workshop
- DEDICATED STOCK SOFTWARE (Logo, Mikro) — widespread in Türkiye
- BARCODE/RFID — physical tracking done automatically
- AN ALERT SYSTEM — an automatic email when stock falls below the minimum
- SUPPLIER INTEGRATION — ordering in a single click
Storage Conditions
- A DRY ENVIRONMENT — moisture causes corrosion (electronics above all)
- A TEMPERATURE OF 5-30°C — conditions that are too cold or too hot damage oil and rubber
- LIGHT — UV degrades some plastic and rubber parts
- AN INVENTORY LABEL — a unique code plus a date on every part
- FIFO (first in, first out) — older stock is used first
- SECURITY — a locked store with a record system
The Spare Parts Problem on Older Machines
- A machine 5+ years old — some parts may no longer be made by the manufacturer
- Suppliers keep their parts stores limited (10 years is the standard)
- A machine 15+ years old — a special order, or an alternative brand
- The strategy: plan your critical parts stock early (in the fifth year)
- Replacing a machine 20+ years old should be considered