Quality Glossary Click here to go to the homepage
Parts Per Million (PPM)
PPM is a way of stating the performance of a process in terms of actual or projected defective material. PPM data can be used to indicate areas variation requiring attention.

a component of technology, product or process that can assume a nominal value that defines it.

Paynter Chart
a matrix of problems, faults, failure types vs. occurrence frequency (days / weeks / months) - named after Marvin (Marv) Paynter (Ford Motor Company).

Percentage of Inspection points Satisfying Tolerance (PIST)
the percentage of inspection points that are within the tolerances indicated on the design.

Process Failure Mode and Effects Analysis. Click here for more on FMEA

Plan-Do-Check-Act (PDCA)
based upon work by W.A. Shewhart (in the 1930s at Bell Labs) and made popular by W.E. Deming (in the 1950s and on), PDCA (also known as the Deming Cycle, Shewhart cycle, or Deming Wheel) is an iterative four-step quality control strategy is based on the principles of - customer satisfaction, management by fact and respect for people. Click here for more.

Product Improvement Program, Performance Improvement Plan
results-oriented approach to project review that involves stakeholders in a process of evaluation and planning to improve product/project performance

P.I.S.M.O.E.A Error Model
P.I.S.M.O.E.A (Part, Instrument, Standard, Method, Operator, Environment & Assumptions) was originally developed by Mr. Gordon Skattum, Senior ASQ CQE, metrologist and Director of Integrated Manufacturing for Rock Valley College Technology Center. The typical statistical assumptions of a Gage R&R study, include: normal process, random and independent trials, stable, and test-retest criteria. When one or more assumption is violated (e.g., non-normal measurement process, operator bias) the tool and analysis ultimately become unstable, confusing, and misleading. %GRR evaluations for product and process control can be overestimated. There are also nonstatistical assumptions related to measurement systems (e.g., calibration, operational, coefficients and rates of expansion, physical laws and constants). The measurement planner should be able to identify, control, correct, or modify the MSA method to accommodate significant violations for the assumptions in the measurement process. Similar to all processes, a measurement system is impacted by random and systematic sources of variation. These sources of variation are due to common and special (chaotic) causes. In order to understand, control and improve a measurement system, the potential sources of variation ought to first be identified. Although the specific causes will depend on the situation, a general error model can be used to categorize sources of variation for any measurement system. There are various methods of presenting and categorizing these sources of variation using simple cause & effect, matrix, or tree diagrams. (source: AIAG's MSA Manual)

Plant Experiments - a process improvement tool, uses simple factorial designs, two-level designs in two or three factors. Goal is to minimize disruption of production while making big enough changes to realize the benefits.

A unit that provides protection and containment of items plus ease of handling by manual or mechanical means.

Pareto Analysis
80/20 rule - focus on the important stuff....

Point Estimate
a statistic, a single number, calculated from a sample. In the absence of a more or better data, a point estimate is the best available estimate for a parameter.

A theoretical, infinitely large sample

The closeness of agreement between randomly selected individual measurements or test results. Also see Accuracy.

Preliminary Bill of Material
An initial Bill of Material completed prior to design and print release.

Prerequisite Tree (PRT)
(part of the Theory of Constraints Thinking Process) a structure describing all of the obstacles to achieving an objective, as well as the responses needed to overcome them, and the sequence in which they must be addressed. It identifies the minimum necessary conditions to achieving a specified objective.

Preventive Action
analyzing possible failure modes and putting in place appropriate action to avoid failure. ex: FMEAs, design reviews and validation, supplier evaluations, preventative maintenance and calibration

Probability Density Function
use in defining a distribution - indicates when a new item is likely to fail.

Process Capability Studies
Process Capability Studies are short-term studies conducted to obtain early information on the performance of new or revised processes relative to internal or customer requirements. In many cases, preliminary studies should be conducted at several points in the evolution of new processes (e.g., at the equipment or tooling subcontractor's plant, after installation at the supplier's plant) These studies should be based on as many measurements as possible. When X-Bar (Xbar) and R charts, at least twenty subgroups (typically three to five pieces, when taking sub-groups) are required to obtain sufficient data for decision making. When this amount of data is not available, control charts should be started with whatever data is available. more here >>
 Cpk=Minimum of (Cpu,Cpl)
Process Capability, Cpk uses 's' or the population standard deviation which is estimated using (Rbar/d2) or (Sbar/C2). Potential Process Capability, Ppk uses the 's' or the sample standard deviation from individual data. Ppk attempts to answer the question "does my 'sample' meet specification?" Cpk attempts to answer the question "does my process meet specification?" A Cp value significantly greater than the corresponding Cpk indicates an opportunity for improvement by centering the process.
Per AIAG handbook - "the process must first be brought into statistical control by detecting and acting upon special causes of variation. then its performance is predictable, and its capability to meet customer expectations can be assessed. this is the basis of continual improvement."
Do not be tempted to rearrange the data in order to get a higher Cpk. data should always be gathered in an appropriate manner (eg: appropriate subgroup size) and ordered by time.

Documented processes that are used when work affects more than one function or department of an organization.

Is a combination of people, equipment, methods, materials and environment that produces output, - a given product or service. A process can involve any aspect of a business.

Process Analysis Tools
Click here

Process Flow Diagram
Depicts the flow of material through the process, including any rework or repair operations.

Product Assurance Plan
A part of the Product Quality Plan. It is a prevention-oriented management tool that addresses product design, process design, and when applicable software design.

Production Part Approval Submissions
The submissions are based on small quantities of parts taken from a significant production run made with production tooling, processes, and cycle times. Parts for production part approval are checked by the supplier to all engineering requirements. 18 Elements of PPAP

Production Trial Run
Product made using all production tools, processes, equipment, environment, facility, and cycle time.

U V W X Y Z Acronyms
Food for Thought !
Search This Site
Custom Search
translate bookmark ©2007 | updated: 8/31/13
translate to french :: courtesy google translate to german :: courtesy google translate to italian :: courtesy italian translate to portugese :: courtesy google translate to spanish :: courtesy google translate to chinese :: courtesy google translate to japanese :: courtesy google translate to korean :: courtesy google translate to turkish :: courtesy google
Add http://www.thequalityportal.com to your delicious accountAdd http://www.thequalityportal.com to your digg accountAdd http://www.thequalityportal.com to your furl accountAdd http://www.thequalityportal.com to your reddit accountAdd http://www.thequalityportal.com to your myyahoo accountAdd http://www.thequalityportal.com to your sync2it accountMeneame
About Us | Contact Us | Visitor Comments