a manufacturing process cannot be released to production until it has been proven to be stable. also, we cannot begin to talk about process capability until we have demonstrated stability in our process. this means that the process variation is the result of random causes only and all assignable or special causes have been removed. in complicated manufacturing processes, such as drilling proces...

Process capability indices (PCIs), Cp, Ca, Cpk, Cpm, and Cpmk have been developed in certain manufacturing industry as capability measures based on various criteria, including process consistency, process departure from a target, process yield, and process loss. It is noted in certain recent quality assurance and capability analysis works that the three indices, Cpk, Cpm, and Cpmk provide the s...

Over the past few years continuously new process capability indices have been developed, most of them with the aim to add some feature missed in former process capability indices. Thus, for nearly any thinkable situation now a special index exists which makes choosing a certain index as difficult as interpreting and comparing index values correctly. In this paper we propose the use of the expec...

Process-capability indices are effective tools for the continuous improvement of quality, productivity and managerial decisions. Statistical process-control techniques improve the quality in mass production. In this study, a process-capability analysis was carried out in the machining line of a medium-sized company that produces machine and spare parts. For this purpose, normal probability plot...

In this paper we propose the use of design capability indices for use in robust design. These indices allow the design requirements to vary within a certain range. Design capability indices are based on process capability indices from statistical process control and provide an alternate approach to the use of Taguchi’s signal-to-noise ratio which is often used for robust design. Successful impl...

Engineering tolerance plays an important role in the process capability analysis for determining whether a manufacturing process is capable of making good quality products. In contrast with the engineering tolerance region in a multivariate manufacturing process, the multidimensional machining process or the nano-cutting process has a special engineering tolerance called the positional toleranc...

Since fuzzy quality data are ubiquitous in the real world, under this fuzzy environment, the supplier selection and evaluation on the basis of the quality criterion is proposed in this paper. The Cpk index has been the most popular one used to evaluate the quality of supplier’s products. Using fuzzy data collected from q P 2 possible suppliers’ products, fuzzy estimates of q suppliers’ capabili...

Abstract Clustering can be defined as the process of grouping physical or abstract objects into classes of similar objects. It’s an unsupervised learning problem of organizing unlabeled objects into natural groups in such a way objects in the same group is more similar than objects in the different groups. Conventional clustering algorithms cannot handle uncertainty that exists in the real life...

Process capability indices (PCI) can be viewed as effective and excellent means of measuring product quality and performance. Several capability indices including Cp, Cpk, and Cpm are well accepted and the implementation of these techniques is successful. The indices Cpu, Cpl, and Cpk have been used previously for evaluating a multi-process product with smallerthe-better, larger-the-better, and...

Process capability indices are widely regarded as a flexible means of evaluating the quality and performance of a process. Accreditation by the Quality System Requirement QS9000 requires an agent to conduct a global evaluation on the process capability over the entire product family from a plant. Generally, the process capability of the whole product family is an important reference for evaluat...