Process Capability Analysis (PCA) is a powerful too l to assess the ability of a process for manufacturing product that meets specific ations. The larger process capability index implies the higher process yield, a nd...Process Capability Analysis (PCA) is a powerful too l to assess the ability of a process for manufacturing product that meets specific ations. The larger process capability index implies the higher process yield, a nd the larger process capability index also indicates the lower process expected loss. Chen et al. (2001) has applied indices C pu, C pl, and C pk for evaluating the process capability for a multi-process product wi th smaller-the-better, larger-the-better, and nominal-the-best specificati ons respectively. However, C pk cannot reasonably reflect the process expected loss. In this paper, index C pn is selected to replace C pk. Indices C pu, C pl, and C pn are used to evalu ate the entire process capability for a multi-process product with smaller-the -better, larger-the-better, and nominal-the-best specifications respectivel y. An integrated process capability index for a multi-process product is propo sed. The relationship between process capability index and the process yield is introduced. A multi-process capability analysis chart (MPCAC), reasonably rev ealing the status of process capability for the entire product, is constructed f or practical application. An evaluating procedure of the process capability for the entire product is also provided.展开更多
In recent years, there has been mounting interest i n measuring process performance in manufacturing industry. Based on analyzing the process capability indices, a production department can trace and improve a poor pr...In recent years, there has been mounting interest i n measuring process performance in manufacturing industry. Based on analyzing the process capability indices, a production department can trace and improve a poor process to enhance quality levels and satisfy customers. The process capabilit y analysis can also serve as an important reference for making decisions for imp roving the global quality of all products. Since C p and C pk are failed to account for process centering, the index C pm is developed. The index C pm takes the process centering into consideration and is su itable for the processes with nominal-the-best type. There are other indices l ike C pu and C pl, and those indices are used for unilateral s pecification processes. Chou (1994) developed a procedure using estimators of C p, C pu and C pl for practitioners to determine whether two p rocesses are equal capability or not. For bilateral specifications processes, i ndex C p is failed to measure process yield and process centering. Thus, th e index C pm is used to develop a similar procedure for practitioners t o determine whether two processes are equal capability or not. The decisions mad e using the procedure to select the better supplier are, of course, more reliabl e.展开更多
Achieving Six-Sigma process capability starts with l istening to the Voice of the Customers, and it becomes a reality by combining th e People Power and the Process Power of the organisation. This paper presents a Six...Achieving Six-Sigma process capability starts with l istening to the Voice of the Customers, and it becomes a reality by combining th e People Power and the Process Power of the organisation. This paper presents a Six-Sigma implementation case study carried out in a magnet manufacturing compa ny, which produces bearing magnets to be used in energy meters. If the thickness of the produced bearing magnets is between 2.35 mm and 2.50 mm, they will be ac cepted by the customers. All the time the company could not produce the bearing magnets within the specified thickness range, as their process distribution was flat with 2.20 mm as lower control limit and 2.60 mm as upper control limit. This resulted in a huge loss in the form of non-conformities, loss of time and goodwill. The process capability of the company then was around 0.40. Organisat ion restructuring was carried out to reap the benefit of the People Power of the organisation. Statistically designed experiments (Taguchi Method based Design o f Experiments), Online quality control tools (Statistical Process Control To ols) were effectively used to complete the DMAIC (Define, Measure, Analyse, Impr ove and Control) cycle to reap the benefit of the Process Power of the organisat ion. Presently the company enjoys a process capability of 1.75, a way towards Si x-Sigma Process Capability.展开更多
文摘Process Capability Analysis (PCA) is a powerful too l to assess the ability of a process for manufacturing product that meets specific ations. The larger process capability index implies the higher process yield, a nd the larger process capability index also indicates the lower process expected loss. Chen et al. (2001) has applied indices C pu, C pl, and C pk for evaluating the process capability for a multi-process product wi th smaller-the-better, larger-the-better, and nominal-the-best specificati ons respectively. However, C pk cannot reasonably reflect the process expected loss. In this paper, index C pn is selected to replace C pk. Indices C pu, C pl, and C pn are used to evalu ate the entire process capability for a multi-process product with smaller-the -better, larger-the-better, and nominal-the-best specifications respectivel y. An integrated process capability index for a multi-process product is propo sed. The relationship between process capability index and the process yield is introduced. A multi-process capability analysis chart (MPCAC), reasonably rev ealing the status of process capability for the entire product, is constructed f or practical application. An evaluating procedure of the process capability for the entire product is also provided.
文摘In recent years, there has been mounting interest i n measuring process performance in manufacturing industry. Based on analyzing the process capability indices, a production department can trace and improve a poor process to enhance quality levels and satisfy customers. The process capabilit y analysis can also serve as an important reference for making decisions for imp roving the global quality of all products. Since C p and C pk are failed to account for process centering, the index C pm is developed. The index C pm takes the process centering into consideration and is su itable for the processes with nominal-the-best type. There are other indices l ike C pu and C pl, and those indices are used for unilateral s pecification processes. Chou (1994) developed a procedure using estimators of C p, C pu and C pl for practitioners to determine whether two p rocesses are equal capability or not. For bilateral specifications processes, i ndex C p is failed to measure process yield and process centering. Thus, th e index C pm is used to develop a similar procedure for practitioners t o determine whether two processes are equal capability or not. The decisions mad e using the procedure to select the better supplier are, of course, more reliabl e.
文摘Achieving Six-Sigma process capability starts with l istening to the Voice of the Customers, and it becomes a reality by combining th e People Power and the Process Power of the organisation. This paper presents a Six-Sigma implementation case study carried out in a magnet manufacturing compa ny, which produces bearing magnets to be used in energy meters. If the thickness of the produced bearing magnets is between 2.35 mm and 2.50 mm, they will be ac cepted by the customers. All the time the company could not produce the bearing magnets within the specified thickness range, as their process distribution was flat with 2.20 mm as lower control limit and 2.60 mm as upper control limit. This resulted in a huge loss in the form of non-conformities, loss of time and goodwill. The process capability of the company then was around 0.40. Organisat ion restructuring was carried out to reap the benefit of the People Power of the organisation. Statistically designed experiments (Taguchi Method based Design o f Experiments), Online quality control tools (Statistical Process Control To ols) were effectively used to complete the DMAIC (Define, Measure, Analyse, Impr ove and Control) cycle to reap the benefit of the Process Power of the organisat ion. Presently the company enjoys a process capability of 1.75, a way towards Si x-Sigma Process Capability.
