Dr. Julan, an American quality management expert, once proposed the concept of the famous quality Trilogy “quality planning, quality control and quality improvement”. The quality management concept and method he advocated has always influenced the development of the world and the world quality management! Among them, the quality control handbook edited by Dr. Julan is known as a masterpiece of quality control science in the world today. It has made outstanding contributions to laying the theoretical foundation and basic methods of total quality (TQM).
As an important part of the quality trilogy, quality control is the verification of quality planning results and an important input to quality improvement. Inspection quality control is also a key module in quality control. Many basic data for quality improvement come from inspection results. Therefore, how to do a good job in product quality inspection and control plays a very important role in the quality of final products and customer satisfaction. We will discuss the control of product inspection quality in the following modules:
Methodology of process control
Many quality practitioners say that 60% of the quality problems can be controlled by controlling the incoming materials. This is very true
Reason; The sources of quality problems are from the following three aspects: incoming material quality, design quality, and process quality; How to do a good job of inspection quality control at all stages?
For the inspection process, taking IQC incoming inspection as an example, we first define the following concepts
Work standard: zero defect, specification drawing, operation instruction
Input: goods sent by the supplier, inspection form
Equipment and facilities: calipers, secondary elements, worktops, proper lighting, etc
Work procedure: IQC incoming material inspection control procedure and XXX inspection specification
Knowledge training: product knowledge, inspection methods, steps, sampling frequency, etc
Output: incoming inspection report + goods with inspection mark
From the above table, we can see that to ensure the quality of inspection control, we must first ensure the correct input of the above five points before we can get the output that meets the standard. This is the most basic methodology for the inspection process! It is also a prerequisite for any inspection work.
After discussing the methodology, we will continue to talk about the specific practices of each inspection process.
Incoming inspection control
Continue the analysis with the process operation mode table in the zero defect process methodology:
Work standard: for work, the work standard of our quality personnel is always zero defect; For specific products,
Our inspection standards are specification drawings, inspection specifications, and sealing samples for sample recognition. At the stage of product design and development, SQE engineers intervene in advance to clarify customer requirements, special characteristics of products, important assembly dimensions and other details, and formulate inspection standards for corresponding products based on them, such as sampling frequency, sampling quantity, inspection methods and tools for key dimensions, appearance, assembly, etc;
Input: for the incoming materials from the supplier, first confirm whether the basic input data of the supplier are complete, such as the delivery inspection report, the label of the outer box, and whether the quantity is consistent with the inspection document;
Equipment and facilities: Planning of the working environment, basic 6S on the inspection site, fixed-point positioning, non inspection, differentiated placement of the products to be inspected, required inspection equipment, such as calipers, two-dimensional elements, three-dimensional elements, etc., light boxes and illumination required for appearance parts, etc;
Work procedures: incoming materials shall comply with the inspection procedures specified by the company, and urgent materials shall be noted in advance to avoid errors due to urgency;
Knowledge training: establish the quality problem record of the corresponding materials as an important input for product knowledge training to ensure that the personnel on duty are familiar with the common failure modes and effects of the corresponding materials, and continuously improve the skills and knowledge reserves of the inspectors through rolling data updating and training;
While doing a good job in the zero defect process mode, for the items that cannot be identified in the routine inspection process of IQC, channels should be established for control. The following two points are particularly important;
1.For periodic type test of products, both the supplier and the organization shall establish periodic type test plan. For organizations with insufficient resources, rolling type test can often be adopted, and some samples are taken every month and quarter for type test to ensure that a complete set of type tests can be completed within one cycle; The source of test items for type test can come from the customer’s requirements, national standards, industrial standards, and enterprise standards formed by the organization’s identification of test items from historical quality accidents. When the author made a heat dissipation product for the host computer of customer a, he found that the product was cracked during the full inspection of the inventory products. Later, he added the test of thermal shock in the first article requirements to verify the reliability of the product;
2.For the annual initial sample of Yis, it is usually impossible to cover all product characteristics for the routine inspection of IQC. However, with the passage of time, some dimensions and characteristics will lead to potential failure risks due to various variations. How can we cover this potential failure risk? We propose the Yis sample signing mechanism for this year, requiring the recognized samples to be re identified every year, and ensure that the variation can be covered through comparison before and after.