This article introduces the different AQL inspection levels available to buyers. Those levels are mentioned in the ISO 2859-1 standard (or its American equivalent, ANSI/ASQC Z1.4). Let’s explore the different levels of random inspections, and how they affect the size of the samples your inspector will pull out of each batch during an inspection. … [Read more...]
3 Examples of Quality Inspection Checklists
Over the years, we have provided feedback to many clients on their product specification sheets and their inspection checklists. Rather than a step-by-step guideline, the most useful is usually to provide them with a few real examples for different types of products. 3 examples of inspection checklists Last year, when personal protective equipment was severely lacking in many countries, we released some of our templates on our commercial website. I believe they … [Read more...]
Factory Management: the 4 Main Roles in the Quality Department
China, as a whole, has 35+ years of experience manufacturing products for export customers. They have accumulated a lot of experience. However, foreign buyers are rather consistently shocked at the level of mismanagement that plagues their factories' quality operations. And fixing it is not that hard. In this article, I will lay out what I see as the 4 basic roles that manufacturers need to fill in their quality department. … [Read more...]
The Basics of Quality Management for Buyers [Podcast]
What's the best way to get started with quality management? It makes a lot of sense to work to improve your product quality coming from Chinese suppliers and you don't need to be a large corporation to do this, but this kind of quality management is best when it follows a process. So in this episode of the podcast, we discuss what the quality management process is, and its 3 main parts: quality planning, quality control, and quality improvement. By understanding how to put measures in … [Read more...]
How to set up a Receiving Inspection: Checklist, Procedure, Reporting form
I have written extensively about pre-shipment inspections (before, during, or after production), always from the perspective of the buyer checking what a supplier is doing; but I noticed that I haven't covered the receiving inspection (also called incoming quality inspections). However, that's a really important topic, so let's get into how to set one up here... … [Read more...]
Why a First Article Inspection Can Save an Entire Production from Quality Issues
Planning the start of production so that a first article inspection can be performed before the rest of mass production takes place... That's not something the average Chinese factory does, unfortunately. However, under the right circumstances, a first article inspection (FAI) can save an entire production from disaster. Here's how... … [Read more...]
Dimensional Control: Should Inspectors Write their Findings?
A few years back, I wrote an article related to dimensional control about the limitations of asking inspectors to write the exact values they find when checking measurements of items like garments and precision mechanical pieces. First, the numbers you can read in a report are not necessarily the reality, and I cited many ways this happens: Use of measurement instruments that are not calibrated (poor accuracy) or that lack precision Inadvertent human errors (misreading the instrument, … [Read more...]
What Is the Confidence Level when Working with AQL Tables?
A reader wrote to me and asked the following question about sampling plans by attributes: What is the "Confidence Level" when using the AQL Tables? How can we determine what the confidence levels are, and are there formulas we can use? That's a valid question. When playing with statistics, one often mentions a confidence interval. For example, "90% of the time, the value will be between 34.5 and 66.0". In theory, I guess one could do the same with the values in the AQL tables. There is a … [Read more...]
A Simple AQL Calculator To Prepare Your Product Inspections
One of our developers prepared this simple AQL calculator for Sofeast. You can use it instead of reading the AQL tables to quickly produce your sample size and permissible defect number. … [Read more...]
When To Do a Random AQL Inspection vs. Check 100% of the Goods
First, let me get one thing out of the way: not all batches need to be checked. If a manufacturer has great systems and processes, and if they have a history of complying with your quality standard, there is usually no reason to send quality inspectors to their facility. Similarly, if you can easily return the whole batch and it can be reworked quickly, you probably don't want to spend resources on checking whether they did as promised. Now, let's assume you do want confirmation of … [Read more...]