Behavioral Interview Questions for Quality Control Managers
By Dara Halloran · Under Pressure
What behavioral questions do quality control manager interviews ask? Expect a defect your inspection missed, a time you held product against pressure, a measurement or testing system you found unreliable, an inspector you trained or managed, and a disagreement with production about a borderline result. Answer with real parts, real data and what changed in your checks afterwards.
Quality control and quality assurance overlap, but they are different jobs. Quality assurance designs the system that should prevent defects. Quality control runs the checks that find them: inspection, testing, measurement and the decision about whether product passes. Interviews for quality control managers are therefore close to the line. They ask about specific parts, specific tests and specific decisions made at the end of a shift.
Substance over polish
Quality control panels tend to be technical and sceptical. That works in your favour if your answers are concrete. In a meta-analysis of self-presentation in interviews, Barrick, Shaffer and DeGrassi found that how candidates presented themselves was related to interview ratings more than to later job performance, and that unstructured interviews were the most affected.1 A technical panel running a structured interview is, in effect, trying to look past presentation to evidence. Give them evidence: the part, the measurement, the result.
Escapes
"Tell me about a defect your inspection missed." Choose a real one. How it was found (often by the customer), how you contained it, why the inspection missed it, and what you changed: the sampling plan, the method, the gauge, the training.
"Tell me about the worst batch you've had to deal with." Containment first, then root cause, then the change.
Holding product
"Tell me about a time you held product against pressure to release it." What the evidence was, who wanted it released and why, how you communicated the hold, what it cost and what the final decision was.
"Tell me about a borderline result you had to call." The measurement, the specification, the uncertainty in the measurement itself, and how you decided.
Measurement
"Tell me about a measurement or testing system you found unreliable." This is where strong quality control candidates stand out. Show how you found it (repeatability checks, conflicting results, a customer complaint), what you did about it, and what it changed in how results were trusted.
"How do you decide how much to inspect?" Show your reasoning about risk, sampling and cost, with an example where you changed the level of inspection.
People
"Tell me about an inspector you trained or managed." How you checked their judgement was consistent with others', and what you did when it was not.
"Tell me about a disagreement with production about a result." How you kept it about the data, and how it was resolved.
The numbers to have ready
Defect rates found in-house and escapes to customers, before and after your changes; the volume and types of product you inspected; any measurement system results; the size of your team; and the cost of scrap and rework if you tracked it.
What to ask the panel
Your own questions show how you think about quality. Ask what the escape rate to customers has been over the last year and what drove it, how inspection results are fed back to production, how often measurement systems are checked, and who has the final say when quality and production disagree about a borderline lot. The last answer tells you a great deal about whether the job is real.
One answer, told well
"Our customer found three cracked housings in a shipment that had passed our visual inspection. I quarantined the remaining stock and we re-inspected it under magnification, finding twelve more. The cracks were too fine to see reliably under our standard lighting at line speed. We added a dye-penetrant check on a sample of every batch and changed the lighting at the inspection station. There were no further escapes from that product in the following year, and the sample check found two bad batches before they shipped."
For the broader quality system questions, see behavioral interview questions for quality assurance managers, and for the structure of every answer, the STAR technique.
References
- Barrick, M. R., Shaffer, J. A., & DeGrassi, S. W. (2009). What you see may not be what you get: relationships among self-presentation tactics and ratings of interview and job performance. Journal of Applied Psychology, 94(6), 1394–1411. https://doi.org/10.1037/a0016532