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The Complete Lean Shop
Glossary - R

r Chart - A variables chart that monitors the dispersion of a process.

chart - A variables chart that monitors the dispersion of a process.

RABQSA International -
Organization that designs, develops and delivers personnel and training certification sources.

Radar Chart - A radar chart is a graphical display of the differences between actual and ideal performance. It is useful for defining performance and identifying strengths and weaknesses.


Random Cause -
A cause of variation due to chance and not assignable to any factor.

Random Distribution - A distribution that forms no particular shape.

Random Sample - A sample that allows every item in a population to have an equal chance of being selected, with no bias.

Random Sampling -
A commonly used sampling technique in which sample units are selected so all combinations of n units under consideration have an equal chance of being selected as the sample. OR Sample units that are selected in such a manner that all combinations of n units under consideration have an equal chance of being selected as the sample.

Random Variation - 
Variation that is uncontrollable.

- A condition in which any individual event in a set of events has the same mathematical probability of occurrence as all other events. Random individual events are not predictable but a large number of them will form a definite pattern or distribution.

- (1) A measure of the variation in a set of data. It is calculated by subtracting the lowest value in the data set from the highest value in that same set. (2) Range is an estimate of spread in a set of data points; the difference between the highest and lowest values in the data set.

Range (Statistical) -
The measure of dispersion in a data set (the difference between the highest and lowest values).

Range Chart (R Chart) -
A control chart in which the subgroup range, R, evaluates the stability of the variability within a process.

Rapid Prototyping -
A process that avoids creating conventional tooling thereby limiting investment expense while new parts or products are tested for feasibility of manufacture.

Reactive Customer-Driven Quality (RCDQ) -
 A state that is characterized by a supplier “reacting” to the quality expectations of a customer rather than proactively anticipating customer needs and expectations.

Readiness -
 Used in a leadership context, the term refers to the extent to which a follower has the ability and willingness to accomplish a specific task.

Ready-Fire-Aim -
 A method that focuses on getting new technology to market and then determining how to sell the products.

Reality Tree
- A cause-and-effect tree (current or future), construction of which is governed by rigorous rules of logic (one of the theory of constraints tools.

Recall Procedures -
 Steps for taking defective products from market. For example, Tylenol and Firestone Wilderness AT tires used these procedures to recall their products.

Red Bead Experiment -
An experiment developed by W. Edwards Deming to illustrate it is impossible to put employees in rank order of performance for the coming year based on their performance during the past year because performance differences must be attributed to the system, not to employees. Six people, 800 red beads and 3,200 white beads are needed for the experiment. The participants’ goal is to produce white beads, because the customer will not accept red beads. One person begins by stirring the beads in a jar and then, blindfolded, selecting a sample of 50 beads. That person hands the jar to the next person, who repeats the process, and so on. When everyone has his or her sample, the number of red beads for each is counted. The limits of variation between employees that can be attributed to the system are calculated. Everyone will fall within the calculated limits of variation that could arise from the system. The calculations will show there is no evidence one person will be a better performer than another in the future. The experiment shows that it would be a waste of management’s time to try to find out why, say, John produced four red beads and Jane produced 15; instead, management should improve the system, making it possible for everyone to produce more white beads. OR Carried out at each of Deming's 4-day seminars. Workers try to satisfy the customer by scooping out only white beads from a mixture of beads that is 80% white and 20% red . Each tries five times, all using the same tools and methods and under strict supervision (Deming!). Regardless of how hard people try to do well, results vary from one try to the next and "rankings" among the workers change. Lessons learned include: a) there is inherent (common cause) variation in every process; b) in such stable processes results we often view as individual "performance" are mostly due to the process or system, rather than the individual; c) there is not much the workers can do about the variation produced the problems must be corrected by management; d) ranking of individuals based on such performance measures in not only meaningless, but destructive to the individuals in the system. These are important and powerful lessons for anyone responsible for supervising or evaluating another person's performance.

Redundancy -
 A technique for avoiding failure by putting backup systems in place that can take over if a primary system fails. For example, many redundant systems are used on the space shuttle to protect the crew if a primary system fails.

Re-Engineering -
(1) A breakthrough approach for restructuring an entire organization and its processes. (2) The redefinition and improving of a company's internal processes based on "Best Practice" standards. (3) A method for making rapid, radical changes to a company’s organization and processes; (4) Taking apart a competitor’s products to see how they are designed and then designing similar ­products.

Registrar -
Generally accepted U.S. equivalent term for “certification body.”

Registration to Standards -
A process in which an accredited, independent third-party organization conducts an on-site audit of a company’s operations against the requirements of the standard to which the company wants to be registered. Upon successful completion of the audit, the company receives a certificate indicating it has met the standard requirements. In countries outside the United States, this generally known as certification.

Registration -
The act of including an organization, product, service or process in a compilation of those having the same or similar attributes.

Regression aka Regression Analysis
- A defined process for quantifying and modeling the output of a process relative o its input variables. It estimates the relationship between inputs and outputs of a process and produces mathematical model of that relationship. Its use can lead to a better understanding of the critical factors controlling ht equality of the process output.

Regression Analysis -
A statistical technique for determining the best mathematical expression describing the functional relationship between one response and one or more independent variables.

Rejection Number -
The smallest number of defectives (or defects) in the sample or samples under consideration that will require rejection of the lot.

Relations Diagram -
See interrelations diagram

Relationship Management -
 A method for developing long-term associations with customers.

- Propensity for failure of a product or component. The probability that an item will continue to function at customer expectation levels at a measurement point, under specified environmental and duty cycle conditions. The ability of an item to perform a required function under stated conditions.

Reliability Engineering
- Engineering function dealing with the principles and practices related to the design, specification, assessment, and achievement of product or system reliability requirements and involving aspects of prediction, evaluation, production, and demonstration

- (1) The probability of a product’s performing its intended function under stated conditions without failure for a given period of time. (2) Propensity for failure of a product or com­ponent.

Repeatability -
(1) The variation in measurements obtained when one measurement device is used several times by the same person to measure the same characteristic on the same product. (2) Repeatability refers to variation in a series of measurements that have been taken with one gage measuring one characteristic of the same item by the same person.

Replications - Number of runs of an experiment.

- taking a material (in-spec or out-of-spec) and reintroducing it to an existing (validated) process.

Reproducibility -
(1) The variation in measurements made by different people using the same measuring device to measure the same characteristic on the same product. (2) Reproducibility refers to variation in a series of measurements that have been taken with one gage measuring one characteristic of the same item by different people.

Requirements - The ability of an item to perform a required function under stated conditions for a stated period of time. OR need or expectation that is stated, generally implied or obligatory - ISO9000 3.1.2

- The difference between a datum and the value predicted for it by a model. If linear regression is performed properly, the sum of the residuals from the regression line must be zero; otherwise, there is a computational error somewhere.

Residual Error
- Experimental error

Resource Utilization -
Using a resource in a way that increases throughput.

Response Surface Modeling
- A process or product optimization technique, related to factorial experiments, that uses a “contour map” of the output variable as a function of two input variables. This map gives a way to discover and specify conditions of robust product and process performance.

- A duty or obligation. In work, often those tasks, functions, processes or results which have been assigned to the individual which the individual is expected to do or to manage. In systems thinking, it is recognized that the "assignment of responsibility" does not mean that the "responsible" person or group of people actually has control over all the factors that affect the outcome. Too often, individuals or groups are blamed or credited undeservedly for the effects of the system (also see Accountability).

Responsiveness -
 A dimension of service quality that refers to the willingness of the service provider to be helpful and prompt in providing service.

Results -
The effects that an organization obtains at the conclusion of a time period.

Reverse Engineering -
 The process of dismantling a competitor’s products to understand the strengths and weaknesses of the designs.

Reward System
- In some cases this may refer only to such tangible elements as compensation and benefits, but typically this term also includes such intangible "rewards" as formal and informal recognition, praise or criticism, "perks", differential treatment by supervisors, being "included", access to information and many other considerations. Reward systems are powerful influences on organizational and employee behavior and need careful consideration and design to assure alignment with the aim and principles of the organization.

- Activity or effort required to convert an otherwise unacceptable outcome of a process into an acceptable outcome.

Right Size -
Matching tooling and equipment to the job and space requirements of lean production. Right sizing is a process that challenges the complexity of equipment by examining how equipment fits into an overall vision for workflow through a factory. When possible, right sizing favors smaller, dedicated machines rather than large, multipurpose batch processing ones.

Right The First Time -
The concept that it is beneficial and more cost effective to take the necessary steps up front to ensure a product or service meets its requirements than to provide a product or service that will need rework or not meet customer needs. In other words, an organization should engage in defect prevention rather than defect detection.

Risk Management -
Using managerial resources to integrate risk identification, risk assessment, risk prioritization, development of risk handling strategies and mitigation of risk to acceptable levels.

- A product or service designed in such a way that it can be readily produced in the presence of variation without defects or costly process treatment and with little variation or, to be designed to function properly in the presence of environmental variation.

Robust Design -
 Designing such that an increase in variability will not result in defective products.

Robust Process
- A process with output variability that is not sensitive to the normal variation from its input variables.

Robustness -
The condition of a product or process design that remains relatively stable, with a minimum of variation, even though factors that influence operations or usage, such as environment and wear, are constantly changing.

Rolled Throughput Yield
- aka - RTY

Root Cause
- To prevent continuing recurrence of an undesirable outcome, problem-solvers need to "peel back the layers" to find the underlying or "root" causes. One technique for doing this is to ask "why did this happen?" And then to the reply to that question, ask "why?" Again. By the process of asking "why?" Several times in this fashion, one gets closer to the root cause. The early answers to the inquiries are more likely to be symptoms of more fundamental problems. OR A factor that caused a nonconformance and should be permanently eliminated

Root Cause Analysis
- Study of original reason for nonconformance with a process. When the root cause is removed or corrected, the nonconformance will be eliminated.

– Risk Priority Number

Run chart - A run chart is a simple line chart that plots one characteristic over time. It is used to plot individual observations and detect patterns in the data.