Inspection and sorting decide complaints: a fix for component makers

At half past five the dispatch lorry is backed up to the loading bay. On the hydrotest bench, a gate valve is under shell pressure, and the hold time has a few minutes left. The supervisor leans in and asks whether it is done yet. The tester, three months into the job, releases the pressure early and stamps the tag. Two weeks later a process plant reports the valve weeping at the seat. On the owner's desk it looks like a quality lapse. It began as a decision about who sits at the bench.

Our page on people issues in component plants lists this pattern: final checks are dull, slow and poorly paid, and that is exactly where customers find defects. It holds for every member trade, from bolt sorting to valve assembly and test.

• Fasteners: long sorting tables under tube-lights, picking out cracked heads, short threads and strays from another size.
• Bearings: noise and vibration checks after greasing, plus visual checks on raceways and shields.
• Valves: shell test and seat test on the hydrotest bench, then nameplate, paint and crating.
• Pipe fittings: air-under-water or hydraulic leak tests, then thread checks with plug and ring gauges.
• Springs: load and free-length testing, then counting into cartons by weight.
• Hydraulic and pneumatic parts: pressure hold or pressure-decay rigs, and function tests on spools and cylinders.

Of all the places to find a defect, the customer's goods-inward is the dearest. The buyer may stop their own line. They may ask you to send people to re-sort stock at their gate, at your cost. A debit note follows. Worse, the purchase team starts to question your share of the schedule. One stray bolt in a carton of thousands can trigger all of this.

Inside the plant, the bill is blame. Machining says the casting was porous. Assembly says the seal kit was short. The tester gets shouted at because he is the last name on the tag. People in final check learn that catching a fault brings trouble and missing one brings worse trouble. Many leave.

• Newest hands go to the bench. Sorting and packing are where new joiners and contract workers are placed first, because the work looks simple.
• No grades. A sorter with five years behind her earns what a sorter with five days does.
• Pay by count or weight. Earnings rise with speed, so stopping to pull a doubtful part costs the sorter money.
• Pressure from dispatch. Hold times shrink once a lorry is idling outside, and nobody holds written authority to refuse.
• Eye fatigue is ignored. Hours of looking at small parts under poor light, with no rotation, blunts attention by mid-shift.
• Complaints never reach the bench. Returns are discussed in the office, not with the people who could have stopped them.
• Catches earn nothing. A machinist is praised for output. A sorter who stops a mixed lot hears nothing at all.

Walk the final gate on each shift. For every person there, note three facts. How many months they have held the role. Whether anyone showed them the defects that matter. How their pay is worked out. Then take the last six customer complaints and trace each one to the shift and bench that passed it. In most plants a pattern appears within an afternoon. The newest person, the shortest hold or the busiest dispatch hour usually sits behind the escapes.

1. 1

   Grade the final-gate roles

   For example sorter, senior sorter, final inspector and test bench lead. Each grade lists the defects, gauges and tests the person can handle alone, with a short practical check to move up.

2. 2

   Put boundary samples at every bench

   Keep labelled good, borderline and reject pieces where sorters and testers can see and handle them. Replace them when a new defect type appears.

3. 3

   Fix light and rotation

   Use magnifying lamps where parts are small. Rotate people between sorting, counting and packing every couple of hours to rest the eyes.

4. 4

   Write down the authority to hold a lot

   The test bench lead and final inspector can stop dispatch on a doubtful lot. The rule is posted at the bench and backed by the plant head.

5. 5

   Walk every complaint back

   Within a week, show the returned part to the bench that passed it and to the station that made the fault. Treat it as a lesson for both benches, never as a hearing.

6. 6

   Credit catches

   Keep a catch-log at each bench. Mention good catches at the start-of-shift huddle and weigh them in grade reviews.

7. 7

   Change how sorting is paid

   Where sorting is paid by count or weight, add a check sample from each sorter's output and pay on accuracy as well as volume.

None of this sticks if final check stays the worst-paid corner of the plant. A grade ladder lets a careful sorter become an inspector, and an inspector become a bench lead. Measures matter too. Rejection found in-house is good news compared with returns from the customer, and measures should say so. Ideas for that sit with performance measures in fastener plants. Who signs the final release is a separate question, covered in who should own final test sign-off.