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The Operations Plan
Published in David C. Kimball, Robert N. Lussier, Entrepreneurship Skills for New Ventures, 2020
David C. Kimball, Robert N. Lussier
The end result of the production/operations process is the conversion of materials into the final product. It should be recognized that the production process is not pure. That is, while we are producing the goods and services we want, there are other products being created that may have unintended consequences. These products may be extremely costly to society. For example, the generation of electric power from coal has indirectly caused black lung disease among coal miners and air pollution in areas surrounding generating plants. Although we cannot completely avoid producing unwelcome by-products, a great deal of time, energy, and money is going into determining either alternative production methods or ways to cope with these outcomes. The elements of a production process are shown in Exhibit 8–2. In order to ensure that the process produces goods or services in the most efficient manner, the process must be controlled. Some of the control mechanisms are also shown in Exhibit 8–2.
Production data evaluation analysis model: a case study of broaching machine
Published in Journal of the Chinese Institute of Engineers, 2021
Chun-Min Yu, Kuen-Suan Chen, Yun-Yu Guo
The products processed by machine tools generally have multiple quality characteristics, including smaller-the-better (STB), larger-the-better (LTB), and nominal-the-best (NTB). Each quality characteristic must meet its respective quality level requirements to ensure the quality of the final product (Chen, Huang, and Li 2001; Chen and Chen 2016; Hsu, Chen, and Yang 2016). As global economic growth slows, the quality of machine tools will exert a direct impact on the quality of the products that they process. To increase machine-tool reliability and overall product quality and enhance the competitiveness of machine-tool manufacturers, process quality must be increased for all parts and components (Chen, Chen, and Li 2005; Huang, Chen, and Chang 2010). Due to the fact that the Six Sigma quality index (SSQI) proposed by Chen, Chen, and Chang (2017) directly reflects process yield as well as process quality levels, we employed SSQIs to construct a process quality analysis chart for products with multiple quality characteristics. This chart can be used to assess the process capabilities of machining processes and make suggestions to improve the process capabilities of quality characteristics with poor quality. As broaching machines offer high production efficiency and are simple in structure and operation, we used broaching machines as a case study to construct a model for process capability evaluation, analysis, and improvement. We first used the accuracy and precision indices defined by Chang, Wang, and Chen (2014) as the horizontal and vertical coordinates, respectively. We next derived the relationships between the quality level of the product and those of individual quality characteristics to establish quality assessment standards and define the acceptable-quality zone, in which process quality meets requirements, as well as the poor-quality zone, in which process quality does not meet requirements. We followed the concepts presented by Chen, Chen, and Chang (2017) and Chen (2019) and used mathematical programming to find the corresponding coordinate point of the upper confidence limit for six sigma quality indices. Process engineers need only check whether the corresponding coordinate points fall in the acceptable-quality zone or the poor-quality zone to identify critical-to-quality characteristics (CTQs). Finally, we used a cause-and-effect diagram (fishbone diagram) to determine the causes of poor process quality and formulate suggestions for improvement.