In-Line inspection
Quality control is essential for any company which wants to succeed in the market. In order to ensure the quality of products, final inspection is very important. However, it is not less important to conduct inspection during the production, ...
Quality control is essential for any company which wants to succeed in the market. In order to ensure the quality of products, final inspection is very important. However, it is not less important to conduct inspection during the production, i.e. in-line inspection. This approach of inspection helps to control the quality of products by helping to fix the sources of defects immediately after they are detected.
Prospective users:
In-line inspection is useful for any factory that wants to improve quality and productivity, reduce defect rates, and reduce re-work and waste.
This practice can be applied to all kinds of factories.
ProblemS addressed
- Product defects due to common sources of mistakes
- A variety of minor defects which can be fixed immediately
- High levels of waste due to defective products
Process
In-process inspection/testing is conducted to ensure that the product/process conforms to specified requirements. The inspection/testing is normally carried out by production personnel. Random audits of the in-process inspection/testing process are conducted by quality control personnel.
To implement in-line inspection, it is necessary to identify in-line inspection check points of the product which are the key points that workers need to check during the production process, as well as provide any samples of defects as an aid for workers to carry out in-process inspection.
Steps in implementation
- The purpose of the in-process inspection is to further pinpoint problems with the system that need correction and also to identify errors earlier in the process.
- In-process inspection can be implemented by line workers with the audit of QC staff.
- Set up pre-determined in-process inspection points to help the workers to implement the inline inspection. Samples of the range of defects should be developed and displayed so that quality control staff can see and access them easily. All of this inline inspection aids should be clear, easy to see and understand with visual aids and made available at the production line.
- Develop and use an in-line inspection checklist or report to record the frequency of each type of mistake “See GPG #03: “Using Inspection Checklists for QC”.
- Conduct training for line workers on how to conduct in-process inspection and use the in-process inspection points and samples.
- The workers perform their own in-process inspections before they perform their normal tasks.
- A reject ticket can be filled when a defect detected to identify the rejected product.
- Defective products should be sorted into different types, e.g. easy to fix the errors or substantial re-work required.
- Products with minor defects that can be easily repaired should be returned to the previous operators in the line for rapid repair, with its reject ticket. This also helps workers to learn from their mistakes and avoid them in the future. Once the error is fixed by the previous operator and the corrective action is annotated on the reject ticket, the corrected items are re-inspected.
- If there are any significant mistakes in line, use devices such as lights, marks or flags to highlight the problems in line for a quick response.
- Random audit of inline inspection can be conducted by QC staff. QC staff can select a random number of products in the production line inspected by line workers to check for certain types of defects. Any defects detected should be recorded and feedbacks should be provided to the line managers to conduct instant fix or reminding the workers.
- In-line inspection quality control staff should wear a uniform (shirt or hat) to distinguish them from the workers and other quality control staff.
- Quality control staff should be provided with sample defects and in-line inspection checklists to record the defects.
- Data on the defects detected during inline inspection should be stored and used for statistical quality control by QC division.
- Training of workers to conduct inline inspection
- At least one in-line quality control staff member per line
- List of inline inspection points
- Reject tickets available for all workers
- Additional inspection efforts
- May create unwanted stress on workers
- Workers may focus more on production rather than in-process inspection
- Reduce end-line defects.
- Save time and efforts of final inspection.
- Help to fix the problems from the roots, and prevent common problems being made repeatedly.
- Help to ensure quality of the products of a production line.
- Workers know how to conduct simple in-process inspections
- Inline inspectors assigned
- Inline inspection is conducted in all working shifts
- Inline inspection reports filled with all observed defects
- Simple defects are fixed immediately.
Funding for the Factory Improvement Programme is provided by the Swiss State Secretariat for Economic Affairs and the United States Department of Labor.
