Search results
Results From The WOW.Com Content Network
Recommended minimum process capability for two-sided specifications Recommended minimum process capability for one-sided specification Existing process 1.33 1.25 New process 1.50 1.45 Safety or critical parameter for existing process 1.50 1.45 Safety or critical parameter for new process 1.67 1.60 Six Sigma quality process 2.00 2.00
In statistical process control (SPC), the ¯ and R chart is a type of scheme, popularly known as control chart, used to monitor the mean and range of a normally distributed variables simultaneously, when samples are collected at regular intervals from a business or industrial process. [1]
The value 3.267 is taken from the sample size-specific D 4 anti-biasing constant for n=2, as given in most textbooks on statistical process control (see, for example, Montgomery [2]: 725 ). Calculation of individuals control limits
The process capability is a measurable property of a process to the specification, expressed as a process capability index (e.g., C pk or C pm) or as a process performance index (e.g., P pk or P pm). The output of this measurement is often illustrated by a histogram and calculations that predict how many parts will be produced out of ...
Process Window Index for a thermal process. Green blurbs denote that the PWIs are within specification, red depicts out of specification. To help determine the capability of a process, statistically determined upper and lower limits are drawn on either side of a process mean on the control chart. [2]
A tolerance interval (TI) is a statistical interval within which, with some confidence level, a specified sampled proportion of a population falls. "More specifically, a 100×p%/100×(1−α) tolerance interval provides limits within which at least a certain proportion (p) of the population falls with a given level of confidence (1−α)."
Typically, a supplier performs the FAI and the purchaser reviews the report. The FAI process usually consists of fully testing and inspecting either the first part produced by the new process or a sample from the first batch of parts. First article inspection is typically a purchase order requirement of the purchaser for the supplier to complete.
The sign test is a statistical test for consistent differences between pairs of observations, such as the weight of subjects before and after treatment. Given pairs of observations (such as weight pre- and post-treatment) for each subject, the sign test determines if one member of the pair (such as pre-treatment) tends to be greater than (or less than) the other member of the pair (such as ...