Quality Terminology / Quality Abbreviations / Glossary - 2

 Voice of the Customer:

Customer feedback both positive and negative including likes, dislikes, problems and suggestions. 

Voice of the Process
Statistical data that is feedback to the people in the process to make decisions about the process stability and/or capability as a tool for continuous improvement.

T-test
used to test means or location effects. For example, used to compare the mean output of Line A vs. the mean output of Line B. [Statistical inference tests to compare the quality of different products / processes and compare the performance of different groups. 

Takt Time
Takt is the heartbeat of a lean system. It is the rate of customer demand. It is the tool to link production to the customer by matching the pace of production to the pace of actual final sales. It defines the rate which material and product flow through the value stream. First, you calculate actual takt times for each product and part (takt time = total time available for production / customer demand, where, customer demand = total production requirement / total available production time). It is used to design assembly and other processes, to assess production conditions, calculate pitch, develop material handling processes, and determine problem-response requirements, and so on. To run faster than takt time anywhere in the value stream is overproduction, resulting in excess inventory. To run slower than takt time creates the need for accelerated production, overtime, and expedited shipments. (Takt is the German word for musical meter, which came into Japan in the 1930s when the Japanese were learning aircraft production from German aerospace engineers. 

Team Feasibility Commitment
A commitment by the Product Quality Planning Team that the design can be manufactured, assembled, tested, packaged, and shipped in sufficient quantity at an acceptable cost, and on schedule. 

Timing Plan
A plan that lists tasks, assignments, events, and timing required to provide a product that meets customer needs and expectations. 

TMAP / TMP - Thought Process Map
helps present thoughts and any questions at the start of the project in a structured, visual way with respect to realizing the project goal. It helps identify all information and progress through a DMAIC process

 

Tolerance Design
A technique using Taguchi Methods or Design of Experiments to identify how much each tolerance contributes to the final Quality and Reliability to help the engineer decide which tolerance to improve and which tolerance to relax. Tolerance design increases product / manufacturing cost and should be done when parameter design has not sufficiently reduced variation. 

Touzen
unnecessary kaizen 

TQM
an approach for continuously improving the quality of goods and services delivered through the participation of all levels and functions of the organization. 

Type I & Type II Errors
Type I error (also known as alpha error) - conclude a difference exists when no difference exists. (For example, you say two machines produce different mean outputs when they do not.).
Type II error (also known as beta error) - conclude no difference exists when it does. (For example, say two machines produce similar mean outputs when in fact they do).
Notes:
a) for fixed sample size experiments, reducing Type I errors result in higher Type II errors. (and vice versa) b) increase in sample size (n), generally reduces both types of errors c) very large sample sizes may result in detecting "statistically significant, but practically insignificant results".
To determine if something is statistically significant, we typically calculate a p-value. To determine statistical significance - a) if p-value is <= alpha, conclude statistical difference, b) if p-value is > alpha, fail to conclude difference. For most experiments: let alpha = 0.01 or 0.05; may tighten alpha if effect of Type I Error is very severe. In terms of statistical significance, (1-p) represents your confidence that a statistically significant difference exists. 

Spider Diagram
A visual reporting tool for the performance of a number of indicators. Also known as "radar chart" this tool makes visible the gaps between the current and desired performance. 

Stable Process
a process which is free of assignable causes (in statistical control - a quantitative condition which describes a process that is free of assignable / special causes of variation).

Stability
is the total variation in the measurements obtained with a measurement system (gage) on the same master or part when measuring a single characteristic over an extended time period. Also known as drift. 

Statistical Control
Is the condition of a process from which all special causes of variation have been eliminated and only common causes remain. Statistical control is evidenced on ,a control chart by the absence of points beyond the control limits and by the absence of any non-random patterns or trends.  

Stratification
A process of grouping data according to a common characteristic.  

Submission Level
Refers to the level of evidence required for production part submissions. (Refer to the PPAP manual and/or Local PPAP Addendum)

 Subsystem

A major part of a system which itself has the characteristics of a system, usually consisting of several components.

 

Suppliers
Suppliers are defined as providers of: a) Production materials. b) Production or Service parts. c) Heat treating, plating, painting or other finishing services directly to Ford. 

Synectics
developed by W Gordon (1961), this method uses analogies and metaphors trigger idea generation. This method is based on the fact that the mind is more productive when dealing with a new or foreign environment. the analogous situation takes the individual away from the exact problem at and requires him/her to consider a related problem.

System
A combination of several components or pieces of equipment integrated to perform a specific function.

7-Step Method
Process Mapping methodology - define scope, document all tasks, categorize value-add vs. non-value add tasks, list internal and external Y's, list internal and external X's, classify X's as being control, standard operation or noise factor, identify data collection points. 

3R's
The three fundamental steps of recording, recalling and reconstructing which most innovators go through when generating new product ideas.

Rational Subgroup
A rational subgroup is one in which the samples are selected so that the chance for variation due to special causes occurring within a subgroup is minimized, while the chance for special cause variation between subgroups is maximized. The key item to remember when developing a sampling plan is that the variation between subgroups is going to be compared to the variation within subgroups. Taking consecutive samples for the subgroups minimizes the opportunity for the process to change and should minimize the within-subgroup variation. The sampling frequency will determine the opportunity the process has to change between subgroups. The variation within a subgroup represents the piece-to-piece variation over a short period of time. Any significant variation between subgroups would reflect changes in the process that should be investigated for appropriate action. Source: AIAG SPC Manual

Random Sample
A sampling method whereby each service output in a lot has an equal chance of being selected.

Random Sampling
A method of looking at a few individual items in a lot to determine the quality of that lot against a standard.

Red Rabbit Test
used to check how long it takes to identify a defect. In this test, a red part is added to the mix and the time until it is discovered is identified. 

Registered Suppliers
Registered Suppliers are suppliers who have received third party registration to a specific quality system standard for the commodity supplied. 

Reliability
The probability that an item will continue to function at customer expectation levels at a measurement point, under specified environmental and duty cycle conditions. 

 Rengi System
formal decision process

 Response Surface Method

a technique to find maximum or minimum condition - the basic strategy is in considering the graph (similar to contours on a topographical map) of the yield as a function of the two significant factors. The higher the hill, the better the yield. 

Rework
Action taken on nonconforming product so that it will meet the specified requirements 

Risk Analysis
Risk analysis has a primary purpose of answering two questions - 1. what can go wrong? and, 2. if something does go wrong, what is the probability of it happening & what are the consequences? 

Robust Design
The design of products to be less sensitive to variations, including manufacturing variation, environment and abuse, increasing the probability that they will perform as intended. It is an integrated system of tools and techniques that are aimed at reducing product or process performance variability while simultaneously guiding that performance towards an optimal setting. Robustness measures are usually implemented for designs that are new so that the best values of the critical functional parameters are uncovered. Robust Design follows the methods first proposed by Genichi Taguchi.  

Root Cause Investigation
Steps involved in conducting a good root cause analysis - 1. understand the goal of the analysis and be objective, 2. obtain a clear understanding of the failure, 3. clearly identify all possible root causes, 4. evaluate the likelihood of each root cause, 5. converge on the most likely root cause, 6. clearly identify and evaluate all possible corrective actions, 7. select the optimal corrective action, 8. verify the corrective action(s) 

Run Order (vs. Standard Order)
Randomizing the standard order (to create a "run order") to determine the order in which run the combinations. (used in DOE)