بهینه سازی هزینه های کیفیت
|کد مقاله||سال انتشار||مقاله انگلیسی||ترجمه فارسی||تعداد کلمات|
|6552||2003||6 صفحه PDF||سفارش دهید||3064 کلمه|
Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)
Journal : Robotics and Computer-Integrated Manufacturing, Volume 19, Issues 1–2, February–April 2003, Pages 135–140
The main goals of quality management in all industries are customer satisfaction by delivery of defect-free products and the radical reduction of defect rates and quality costs in the production. Controlled technological processes are the most important way to reach these goals. These principles are standard in mechanical engineering and are in use with great success. The properties in electronics production are different from the properties in mechanical engineering. During the assembly of electronic devices, processes are sensitive to the influences (environmental, parameter variation, etc.), that act on these processes. These influences are very strong, especially in the production of small batches of assemblies and a high mix of products. Processes can become uncontrolled, the defect rates can rise, and it is necessary to have inspection and repair processes after the different technological processes. But what about the quality costs? Is it sensible to do these quality control steps from the economical point of view? What is the right inspection strategy—no inspection or 100% inspection or statistical process control? To answer these questions new simple and powerful quality cost models have been developed at the Electronics Technology Laboratory and are in use in electronic producing industries. The quality costs are the “measurement system” to compare different inspection strategies with each other. The costs are calculated by the use of mathematical models—the quality cost models. To analyze and optimize the quality processes of a complete production line we use the method “Dynamic Programming”, developed by the American scientist, Bellman in the early 1950s of the 20th century
Controlled technological processes are the most important way to reach a high quality level in mechanical engineering industries. Statistical process control (SPC) and Failure Mode Effect Analysis (FMEA) are other ways to reach this goal. It is possible to use these methods also in electronics production in the case of producing batches with a high number of similar PCBs. But in a production process with many different products and small batch sizes, there are relatively high defect rates and some technological processes may be uncontrolled. The objective of this paper is to show new models to decrease the quality costs of such technological processes. 2. The basic quality cost model At first we look at a chain of technological processes—for instance, a SMT production line as in Fig. 1. The SMT line consists of a PCB transport system, a solder paste printer, a chip shooter, a pick-and-place machine, a reflow oven and an inspection system at the end. In our example the process of solder paste printing should not be well controlled. Consequently, there are some poorly printed PCBs. These PCBs are represented by the defect rate p.
نتیجه گیری انگلیسی
This paper presents an overview to realize optimal test strategies in SMT-manufacturing lines with a view to the costs. It shows the mathematical background of the models. The quality cost models are in use in an electronic production. The necessary steps in practice depend on the concrete quality of the investigated processes and on the complexity of the investigated products.