Key Process about Quality Control and Improvement
As learned from 20-year experience in quality management, I’d like to share with you the process about quality control and improvement.
1. Know customers’ expectations
What markets do you sell to, in what distribution channels? Knowing your customers and end-users will help you answer these questions:
A. What is critical to quality? What is a must-have? What is a nice-to-have?
B. What are issues they don’t want to see? The battery in a widget can’t get recharged, the thickness of the steel used for construction is below tolerance, small color variations on different units that will all be shown on the same shelves…
C. What proportion of defective products (remember, you need to define what is defective in their eyes) can they tolerate?
2. Set objectives and approve samples & checklist
Based on what the above questions led you to discover, the best practice is to:
1. Draft a clear and specific specification sheet, including defining the most common potential defects
2. Set AQL limits
3. Approve samples that have the right touch & feel, and if needed also boundary samples (to illustrate the limit of acceptance)
4. Have the suppliers confirm all these in writing (if possible under the frame of a legally enforceable agreement)
3. Qualify capable suppliers & critical sub-suppliers
If you are setting up the supply chain for a new product, this playbook will go a long way in helping you reach your objectives:
1. Identify the critical components — those with high value and/or those associated with a high risk (and that usually means the highly customized components make that list) — or processes (typically surface treatment such as paint, anodizing, plating…)
2. Use your documented objectives and a relevant auditing checklist to qualify those components’ suppliers
3. In parallel and the same way, qualify the final processing & assembly manufacturer
4. Audit systems & processes, know where the risks are, plan accordingly
As part of the supplier qualification process, you will need to audit their quality systems and maybe also their processes. You will know where the major gaps are, and you will have an idea of the highest risks for your project.
When and where to do ‘Quality Control’
1. Inspect components and products based on identified risks
The critical components may be checked at the suppliers’ facilities, or in the assembler’s facility. And the production can be inspected at several stages. It all depends on the main risks that were identified.
If one process is particularly fraught with uncertainty, for example plating, it can make sense to be present during the pilot run and then during production.
2. Laboratory testing (compliance & safety, reliability)
This is often a complement to the QC inspections. Inspectors can pick samples at random and send them to a lab for testing.
People often think of compliance testing (to make sure you can sell the batch on your market with low legal risks) but much less often of reliability testing (to make sure your products won’t fail too early in the hands of your customers).
Ongoing ‘Quality Improvement’
1. Drive process improvements based on risks and on issues found
Needless to say, working closely with suppliers is a must. They need to be cooperative and open.
2. Set controls based on identified risks
If a manufacturing process lacks a structured way of ensuring good outputs, don’t take several isolated actions.
Taking a holistic approach and setting up a process control plan (and its close cousin, the preventive maintenance plan, if equipment is a common source of issues) will usually lead to faster and more sustainable improvements.
3. Update the quality standard, risk analysis, etc. over time
The planning is not done once and for all. New information surfaces every week. Some suppliers will change, some new defects will come up, some end users will complain, and so forth.
Keep a list of the sources of high risks you have identified and have not sufficiently mitigated. Then, adapt your plan for quality control and your focus for improvements.