List of statistical packages. R (programming language) R is a programming language and software environment for statistical computing and graphics.
The R language is widely used among statisticians and data miners for developing statistical software[2][3] and data analysis.[3] Polls, surveys of data miners, and studies of scholarly literature databases show that R's popularity has increased substantially in recent years.[4][5][6][7] R is highly extensible through the use of user-submitted packages for specific functions or specific areas of study.
Due to its S heritage, R has stronger object-oriented programming facilities than most statistical computing languages. Extending R is also eased by its lexical scoping rules.[19] Statistical process control. Statistical process control (SPC) is a method of quality control which uses statistical methods.
SPC is applied in order to monitor and control a process. Monitoring and controlling the process ensures that it operates at its full potential. At its full potential, the process can make as much conforming product as possible with a minimum (if not an elimination) of waste (rework or Scrap). SPC can be applied to any process where the "conforming product" (product meeting specifications) output can be measured. Reliability engineering. ), as the frequency of failures; or in terms of availability, as a probability derived from reliability, testability and maintainability.
Testability, Maintainability and maintenance are often defined as a part of "reliability engineering" in Reliability Programs. Reliability plays a key role in the cost-effectiveness of systems. Reliability engineering deals with the estimation, prevention and management of high levels of "lifetime" engineering uncertainty and risks of failure. Although stochastic parameters define and affect reliability, according to some expert authors on reliability engineering (e.g. P. Reliability engineering relates closely to safety engineering and to system safety, in that they use common methods for their analysis and may require input from each other. History[edit] The word reliability can be traced back to 1816, by poet Coleridge.[6] Before World War II the name has been linked mostly to repeatability.
Overview[edit] Objective[edit] Sampling (statistics) The sampling process comprises several stages: Successful statistical practice is based on focused problem definition.
In sampling, this includes defining the population from which our sample is drawn. A population can be defined as including all people or items with the characteristic one wishes to understand. Quality control. X-ray zoom series of a network adapter card.
Quality control, or QC for short, is a process by which entities review the quality of all factors involved in production. This approach places an emphasis on three aspects:[citation needed] Elements such as controls, job management, defined and well managed processes,[1][2] performance and integrity criteria, and identification of recordsCompetence, such as knowledge, skills, experience, and qualificationsSoft elements, such as personnel, integrity, confidence, organizational culture, motivation, team spirit, and quality relationships. Controls include product inspection, where every product is examined visually, and often using a stereo microscope for fine detail before the product is sold into the external market. Inspectors will be provided with lists and descriptions of unacceptable product defects such as cracks or surface blemishes for example.
The quality of the outputs is at risk if any of these three aspects is deficient in any way. Engineering Systems Division. 2.830J Control of Manufacturing Processes (SMA 6303), Spring 2008. Statistical Process Control - SPC. The fundamentals of Statistical Process Control (though that was not what it was called at the time) and the associated tool of the Control Chart were developed by Dr Walter A Shewhart in the mid-1920’s.
His reasoning and approach were practical, sensible and positive. In order to be so, he deliberately avoided overdoing mathematical detail. In later years, significant mathematical attributes were assigned to Shewharts thinking with the result that this work became better known than the pioneering application that Shewhart had worked up. The crucial difference between Shewhart’s work and the inappropriately-perceived purpose of SPC that emerged, that typically involved mathematical distortion and tampering, is that his developments were in context, and with the purpose, of process improvement, as opposed to mere process monitoring. I.e. they could be described as helping to get the process into that “satisfactory state” which one might then be content to monitor. So why SPC? Software Quality Assurance within CMMI. The purpose of (CMMI) Technical Solution is to design, develop, and implement solutions to requirements.
Solutions, designs, and implementations encompass products, product components, and product-related life-cycle processes either singly or in combinations as appropriate. This is the main Design and Coding processes. CMMI puts the design and build together. Other important processes, e.g. Configuration Management are listed in other process areas within CMMI. The Red Bead Experiment. The Red Bead Experiment Introduction This experiment can be conducted with a Sampling Bowl or Sampling Box.
While Dr. Deming used 80% white beads and 20% red, you will find this experiment done with 80% white and 20% colored. The colored beads add another dimension to the demonstration. This is a clever demonstration of the futility of most management systems for improving quality. The experiment starts with a sampling device that has 80% white and 20% colored beads, normally red beads, hence the name "red bead experiment". The objective of the bead factory in the demonstration is to make white beads. The Experiment The instructor should take on the role of the department foreman or department supervisor and first of all selects his work team. Foreman: Okay I need eight bodies. So the process goes until all nine people are selected. Back to top What will happen is that each worker will take turns drawing a sample of 50 from the sampling device.
Clear Instructions Bob: Yes I did Intimidation. Statistical process control. Online statistical calculators for acceptance sampling and quality control. Clinical Trial Analysis and Consulting StatWorks Inc RTP. JUSE-Communication on Web (English)