Three types of quality problems in today's work: In - depth analysis of implementation deviations and awareness loopholes
I. Incoming material blending: Inspection failure and blind spots in supplier management under the "inertia of trust"
A long - term cooperative supplier has been included in the "relaxed inspection" list because 12 consecutive batches of incoming materials were qualified. Inspectors only need to conduct a random inspection of the appearance and dimensions at a 10% ratio. On this Monday, due to the production department urging the delivery of an urgent order, after the supplier's materials arrived, the inspector randomly selected 5 boxes (a total of 500 pieces) for testing as usual. As a result, all of them met the requirements of the drawings, and the materials were directly released and put into storage.
On Wednesday, when the mold maintenance workers were preparing to install the mold, they unexpectedly found that there were 20 products from other companies mixed in the incoming materials. The two types of products look similar, but the diameters of the key assembly holes differ by 0.5mm. If they are produced on the same production line, it will cause jams during subsequent assembly and may even lead to the scrapping of the entire batch of products.
After contacting the supplier, I learned that this supplier serves three customers simultaneously. Due to our company's "urgent insertion of an order" this time, the production cycle was compressed from seven days to three days. The supplier was unable to complete the exclusive production on time, so they mixed the finished products (which had passed the inspection but had not been delivered) of other customers into our company's batch, attempting to "pass off the inferior as the superior".
Solutions and Improvements:
- Require the supplier to come to the factory within 24 hours to pick out all the mis-shipped products and rework them, and bear all the rework costs (approximately 8,000 yuan).
- Cancel the relaxed inspection qualification of this supplier and resume full inspection; add batch identification verification — each box must be affixed with our company's exclusive label of order number + batch number, and those without the label will be directly rejected.
- Sign the "Mixed Shipment Breach Clause" with the supplier: Deduct 10% of the payment for the first mixed shipment, and terminate the cooperation for the second mixed shipment.
- Conduct "product feature recognition training" for warehouse and front - line production employees, and produce the "Key Dimension Comparison Card" (including comparison pictures of appearance, dimensions, and markings). Require that "every box must be inspected, and every item must be checked", and report any differences immediately.
II. Omission of process adjustment: The firewall of first - piece inspection and the loose sluice gate of system implementation
During the mold trial of a certain product on Tuesday morning, the process technician found that the original injection molding temperature of 180°C caused surface shrinkage. After adjusting it to 190°C, the mold trial passed. However, due to the urgency to handle a malfunction of another machine, the operation instruction manual was not updated, and the "Process Change Record Form" was not filled out. In the afternoon, after the operator took over the shift, they set the temperature to 180°C for production according to the original process card. Fortunately, the operator strictly carried out the first-piece inspection - immediately checked the standard sample after the first piece was molded, and found obvious shrinkage marks. They notified the process technician to re - debug in a timely manner, thus avoiding batch scrap (with an estimated loss of 12,000 yuan).
Previously, in response to the issue of "no record of process adjustment", the "System for Records of Qualified Commissioning" was formulated. After the process technician completes normal commissioning, they are required to fill in the "adjustment time, parameters, and inspection results" on the console and sign to prove that production can commence. However, this time, the process technician skipped the recording due to being in a hurry, resulting in an incorrect operation.
Reinforcement measures:
- Binding responsibilities: If the process technician fails to complete the records, the operator has the right to refuse production. If there is a violation, both parties shall bear the responsibilities jointly.
- On - site spot - check: The workshop supervisor shall check the "Process Change Record Form" every two hours. If it is not filled out, 10% of the performance appraisal will be deducted.
- Visual reminder: Post a poster reading "Adjust parameters → Test the first piece → Fill in the records" beside the machine to strengthen the memory of operations.
III. Missed inspection of trial - mold errors: The cognitive gap between "understanding" in training and "making mistakes" in execution
When trial - molding a new product on Wednesday, the operator asked the process technician about "the placement direction of the insert". The process card required that "the boss should face the inner side" (to prevent assembly interference), but the process technician orally said it should "face the outer side" based on his experience of last week. The operator produced 3 trial - molding parts according to this. When the process technician and the operator checked the process card, neither of them found the error (the process technician trusted his experience and the operator trusted the process technician). It was not until the QA made an inspection and compared with the process card that the operation was stopped (there was no batch loss).
In - depth exploration of the reasons:
- Implementation deviation: Neither of the two people "checked the key items on the process card word by word". Instead, they made judgments based on experience or trust.
- Lax attitude: The technician did not confirm the instructions in writing, and the operator did not actively request guidance.
- Training transfer: Previously, one-on-one training on process cards was provided, but it has not been transformed into operating habits.
Action plan:
- Double confirmation for trial molding: The process technician shall provide the "Trial Molding Instruction Sheet" (including graphic and text descriptions of placement, parameters, and inspection items). Production can start after the operator signs it. After the trial molding, mass production can be carried out only after the process technician, operator, and QA conduct a joint check and sign.
- Consciousness reinforcement: Hold a reflection meeting using the "cost case of trial - die error" (materials costing 2000 yuan and 4 hours of time), and emphasize "operating according to the documents".
- Training upgrade: Change the process training to "scenario simulation" - simulate the scenario of "wrong oral instructions" and practice "how to verify the process card" and "how to reject oral instructions".
The core of essential quality problems is "the double absence of execution and awareness"
Today's problem seemingly lies in the process loopholes of "inspection, process, and trial molding", but in fact, it is:
- Ignorance of rules: relaxing inspections due to trust, skipping records due to being pressed for time, and neglecting verifications due to experience.
- Slackness in responsibility: The process technician failed to confirm, and the operator failed to inspect.
- Awareness of quality: Failed to translate "every piece being qualified" into the action of "being serious at every step".
In the future, it is necessary to plug loopholes in all aspects of "personnel, methods, and materials" through process standardization (double confirmation, written guidance), system constraints (random inspection of records, responsibility linkage), and awareness enhancement (case training, scenario simulation).