During the design and production of any product, changes and adjustments to the design and process often occur. Also, there may be unplanned line stoppages and switching of production and lines.
So, how to ensure that these changes will not have an impact on subsequent production quality? That’s why first item inspection is important.
Definition of first item inspection
During the production process, after any one or more of the 5M1E (Man, Machine, Material, Method, Environment, and Measurement) production elements have been changed, we have to carry out the first item inspection.
The first item is usually the first or first few products. For mass production, the “first item” often refers to a certain number of samples.
That is, first item inspection is an inspection of the first or first few products processed on the production line at the beginning of each shift or after a change in the process. The number of inspections can be set according to the requirements of different companies or customers. Generally, at least 3-5 items of continuous production need to be inspected and passed before the product can be processed further.
Purposes of first item inspection
The main purpose is to prevent batch out of tolerance, secondary treatment and scrap of products. It is a means of pre-control of the product manufacturing process, an important method of quality control of the product process, an effective and indispensable method for enterprises to ensure product quality and improve economic efficiency.
Long-term practical experience has proved that the first inspection system is an effective measure to detect problems as early as possible and prevent products from being scrapped in batches. Through the first item inspection, systematic causes such as serious wear of fixtures or wrong installation and positioning, poor precision of measuring instruments, misreading of drawings, wrong materials feeding or formulation can be found, so that corrective or improvement measures can be taken to prevent batch failures.
Only after the first item has passed the inspection can it be formally produced.
Timing and occasions for first item inspection
1. Start of each shift.
2. Change of operators.
3. Replacement or adjustment of machines and equipment (including changing or sharpening cutters).
4. Modify machining methods and parameters.
5. Use of new materials.
…
Requirements for first item inspection
The first item inspection adopts three inspection system, including self-inspection, mutual inspection and special inspection.
Self inspection: conducted by operators.
Mutual inspection: conducted by team leaders or colleagues.
Special inspection: conducted by inspectors.
Whether or not the first item has passed the inspection should finally be approved by a specialized inspector. The inspector must mark the first item that passes the inspection and keep it until the shift or batch of products is done. (All first items must be sampled to see if the process has been changed.)
If the first item fails the inspection, it is necessary to find out the reason and take measures to eliminate the fault before re-processing. Three inspection will be conducted again after processing, and only after passing the inspection can it be set as the first piece.
Main projects of first item inspection
1. Match between chart number and worksheet.
2. Match between materials, blanks or semi-finished products and the worksheet.
3. Match the materials and surfaces of the blanks with the positioning of the mounting.
4. Whether the recipe and ingredients meet the specified requirements.
5. Whether the actual qualities and characteristics of the first item conform to the drawings or technical documents.
Summary
To save cost and time, first item inspection is critical in CNC machining.
CYCO is committed to providing our customers with an excellent experience. We ensure that our products meet your requirements and standards through first item inspection before machining, which prevents substandard products from affecting delivery times.
In order to avoid wasting your valuable time, you can choose CYCO as your partner without any hesitation!
Contact us for a worry-free experience now!
