Computer Aided Quality Control (CAQC): Use of Computer in Quality Control

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What is Computer Aided Quality Control or CAQC?

The use of the computers for quality control of the product is called as the computer aided quality control or CAQC. The two major parts of quality control are inspection and testing, which are traditionally performed manually with the help of gages, measuring devices and the testing apparatus. The two major parts of computer aided quality control are computer aided inspection (CAI) and computer aided testing (CAT). CAI and CAT are performed by using the latest computer automation and sensor technology. CAI and CAT are the standalone systems and without them the full potential of CAQC cannot be achieved.

The main objectives of the CAQC are to improve the quality of the product, increase the productivity in the inspection process and reduce the lead times in manufacturing. The implementation of CAQC in the company results in the major change in the way the process of quality control is carried out in the company.

Important Points and Advantages of Computer Aided Quality Control or CAQC

Here are the advantages and the highlights of the computer aided quality control process:

1) 100% testing and inspection: In the traditional manual process the testing and inspection is done by the sampling process out of the hundreds and thousands of products or parts manufactured by the company since it is not feasible to check each and every product. With CAI and CAT hundred percent inspection and testing can be accomplished without much difficulty. With 100% inspection the company does not have to depend on statistical quality control method in which it is assumed that anything less than 100% of quality is acceptable. With computer controlled inspection, it is not necessary for the quality control department to settle for less than perfection.

2) Inspection integrated with manufacturing process: In the traditional process there is separate quality control department where the manufactured product is taken for the inspection and testing. In CAQC the inspection process is integrated with the manufacturing process and it is located along the production line. Thus as soon as the product is manufactured it is tested immediately by the computerized process without moving it to some other location. This helps in reducing the overall time required for manufacturing the product.

3) Use of non-contact sensors: In the traditional process the product or the part to be inspected is handled manually since it has to be positioned properly for inspection on the desk or suitable location. In CAQC non-contact sensors are used for the inspection purpose and they inspect the product without coming in contact with the product. The non-contact sensors operated by the computer are kept along the production line and they can check the product very quickly in the fraction of seconds. In future with further advancements in the technology, the robots would be used to carry-out the inspection process thus further automating and speeding the process.

4) Computerized feedback control system: The data collected by the non-contact sensors is sent as the feedback to the computerized control systems. These systems would carry out the analysis of the data including statistical trend analysis. This helps in identifying the problem going on in the manufacturing line and find appropriate solution to it. For instance, the results from non-contact sensors may indicate that the parts manufactured are not within the acceptable tolerance limits. This would help the production or quality control personnel to find out the precise location of the problem and its exact cause. The corrective action taken quickly saves lots of time and money due to reduced wastages and also improves the quality of the product.

5) Computer aided quality control and CAD/CAM integration: Apart from inspection and testing, computers are used in a number of other areas of the quality control. All the applications of CAQC can be integrated with CAD/CAM to make the whole process of designing and manufacturing controlled by the computers converted into fully automated process.


  1. Book: CAD/CAM: Computer Aided Design and Manufacturing by Mikell P. Groover and Emory W. Zimmers, Jr., Prentice Hall of India Private Limited.