Uw brug naar?

U bent hier: Home » Informatie » Woordenboek


One or more observations drawn from a larger collection of observations or universe (population). Any subset of the population under study i.e. the people of Amsterdam are a sample of the people in The Netherlands. Minimum sample size of a continuous measurement is n=(2s/Δ)2.
Sample Mean
The sample mean, usually denoted by X-bar, is found by summing all the data values in the sample and dividing the sum by the number of items in the sample. It is a measure of central tendency for the sample observations.
Sample Median
A measure of central tendency. It is the value that splits the sample data into two equal groups, one with values greater than or equal to the median and one with values less than or equal to the median.
Sample Mode
A measure of location, defined as the most frequently occurring sample data value. The sample mode is not used very often in statistical procedures.
Sample Standard Deviation
The sample standard deviation is the positive square root of the sample variance and is usually denoted by s.
Sample Variance
A measure of dispersion for a sample, based on the squared deviations of the observed data values about the sample mean. The sample standard deviation is usually denoted by s2.
Sampling bias
Sampling Bias is the impact of factors that causes a sample to be more or less valid. Bias is present in all samples, the objective is to sample in a way that keeps bias to a minimum. A sample that is not valid due to bias is described as a Biased sample. It is important for project teams to design a sampling approach that minimizes bias.
Sampling Distribution
A probability distribution consisting of all sampled values of the population parameter. The notion of a sampling distribution is critical to an understanding of statistical methods because all statistical tests of hypothesis are based on sampling distributions of sample statistics.
Sampling with Replacement
As each element is selected for the sample, it is returned to the population. A previously selected element can be selected again and therefore may appear in the sample more than once.
Sampling without Replacement
Once an element from the population has been selected to be included in the sample, it is removed from the population and cannot be selected a second time.
Scatter Diagrams
Charts which allow the study of correlation, e.g., the relationship between two variables.
Scatter plot
A two dimensional plot to assess the relationship of two variables.
Scope defines the areas that will be looked at within a project (i.e. In Scope) as well as the areas that will be excluded (i.e. Out of Scope). Scope can be defined by terms such as process, function, geography (e.g. outside Amsterdam) or organisational entity (e.g. plant, sales organisation).
Sigma is de Griekse naam voor de Latijnse letter S. De letter S staat in de statistiek voor de standaardafwijking, een maat voor de spreiding. Als we ALLE metingen hebben ofwel van de GEHELE populatie, gebruiken we in de statistiek geen Latijnse maar Griekse letters. De naam Six SIGMA is nu deels duidelijk, sigma staat voor de gehele spreiding. Ook is SIGMA gekozen voor marketingtechnische redenen: Six Sigma bekt lekkerder dan bijvoorbeeld Six Standard Deviation.
Sigma level or sigma quality level (SQL)
A quality that is calculated to describe the capability of a process to meet a specification. A Six Sigma quality level is said to have a 3.4 ppm rate.
p-value; significance level or level of significance; represents the chance that we are willing to take of being wrong when we state the conclusion; usually p is 0.01 or 0.05. It is often represented as the Greek letter α (Type 1 error).
Suppliers-Inputs-Process-Outputs-Customers all key elements of processes.
Six Sigma deployment
A vehicle for strategic change ... an organisational approach to performance excellence.
Six Sigma Methodology
All inclusive methodology (Reactive and Proactive) for selecting and executing projects focused on identifying and satisfying customer needs
Six Sigma or 6σ
Sigma or σ is a letter in the Greek alphabet. The term "sigma" is used to designate the distribution or spread about the mean (average) of any process or procedure. As a business strategy, Six Sigma is the sigma value or metric that indicates how well a process is performing against customer requirements. The higher the sigma value, the better. Sigma measures the capability of the process to perform defect-free work. A defect is anything that results in customer dissatisfaction. The sigma scale of measure is perfectly correlated to such characteristics as defects-per-unit, parts-per-million defective, and the probability of a failure/error. Performing at 6-sigma means that no more than 3.4 defects occur in one million opportunities.
Solution Report
Provides confirmation that a solution will be implemented to deliver the Goal Statement in the Project Charter, and enables the impact on other projects and the Business to be assessed.
The range of data with the upper 5% and lower 5% of data points removed. Some companies use Span as a simple replacement for Standard Deviation.
SPC - Statistical Process Control
This is the application of statistical control techniques (such as control charts and alarm levels) to manage variation within a process. SPC has been in existence for many years and is widely used as a mechanism for identifying and addressing performance problems mainly in manufacturing.
Special or Assignable Causes
Variations in process outputs that are due to factors such as unusual observations, machine tools wearing out, incorrect machine settings, poor-quality raw materials, operator error, and so on. These are causes that can be linked to a specific action, point-in-time, or performance on a specific task. Corrective action will be a decision to change the process at the point when the special cause occurred or the specific action that resulted in the special cause. An assignable cause is often signaled by an excessive number of data points outside a control limit and/or a non-random pattern within the control limits.
Specification limits
The upper and lower performance limits that are specified for a particular process. The objective of the specification limits is to highlight non-conformance and to identify trends in data that may lead to a process moving outside acceptable performance levels.
Sponsor (Project Sponsor)
Responsible for identification and execution of Lean Six Sigma projects. Works with Deployment Champions on project prioritisation and selection. Personally accountable for the performance of the process under consideration and controls the resources associated with the process.
Squared Deviation
The difference between the measured characteristic of individual item in the population and the mean of that characteristic in the population squared. It is used to calculate the variance.
Stable Process
A process which is free of assignable causes, e.g., in statistical control without any shits in location.
Person who will be impacted by the product or process when completed.
De standaardafwijking (S) is een (steekproef)maat voor de spreiding. het is de wortel van de variantie. De term standaarddeviatie wordt ook wel gebruikt in het Nederlands, een wat letterlijke vertaling uit het Engels.
Standard Deviation (s)
A statistical index of variability which describes the spread with a given data set. The standard deviation is the positive square root of the variance and is usually denoted by s. It measures the variability of the sample observations around the sample mean (Xbar).
Standard Error
The standard error is the standard deviation of a sample statistic, such as Xbar. The standard error measures the variability of observations around their expected value. The standard error is used in the determination of confidence intervals.
Standard Normal Probability Distribution
A normal distribution with a mean of zero and a standard deviation of 1.0.
Statistical Control
A quantitative condition which describes a process that is free of assignable/special causes of variation, e.g., variation in the central tendency and variance. Such a condition is most often evidenced on a control chart, i.e., a control chart which displays an absence of nonrandom variation.
Statistical Process Control (SPC)
The applications of statistical methods in the control of processes. Generally the emphasis with SPC is on tools and specifically on SPC charts which plot performance over time comparing the performance to control limits.
Statistische Procesbeheersing
Statistische Procesbeheersing = Statistical Process Control (Eng.) = SPC Uitgangspunt bij SPC is om een beheerst, goed lopend proces ook zo te houden. In die zin kun je SPC reactief noemen. SPC is een statistische beheersingsmethodiek om onbeheerste situaties te identificeren en te signaleren. In de literatuur wordt een onbeheerste situatie Out of Control (OOC) genoemd. Vervolgens moet er iets mee gedaan worden. Dit kan met behulp van een zogenaamd Out of Control Action Plan (OCAP). De regelkaart (control chart), met Shewhart in de jaren '20 als grondlegger, is het hart van SPC. De bekendste regelkaart is de zogenaamde Shewhartkaart.
A document typically a powerpoint presentation that conveys the status of the project by clearly depicting the Lean Six Sigma methodology and tools applied during each phase of the project as well as the results.
The process of breaking data down into groups based on specific criteria. Criteria could includes areas such as type of data (e.g. invoices, production reports, customer service complaints), time (e.g. day, week, month, quarter), location ( e.g. plant, country, region) and owner (e.g. function, department, entity). Stratification is important in Lean Six Sigma because it enables teams to create much greater visibility around what is going on in a process.
Een stroomdiagram is een model of benadering van een proces of systeem. Er zijn vele conventies of standaarden voor de te gebruiken symbolen. Binnen ISO blijft het hierbij, binnen Lean Six SIgma verbeterprojecten is dit het begin om uiteindelijk inzicht in de prestaties van processen te krijgen met behulp van een zogenaamde Value Stream Map.
A logical grouping of objects or events which displays only random event-to-event variations, e.g., the objects or events are grouped to create homogenous groups free of assignable or special causes. By virtue of the minimum within group variability, any change in the central tendency or variance of the universe will be reflected in the "subgroup-to-subgroup' variability.
Sum of Squares (SS)
The deviations from the mean, squared and summed. SS is used to determine the magnitude of the error in a statistical test such as ANOVA or Regression.
SWOT Analysis
This is a qualitative analysis tool designed to assess a company's competitive environment. SWOT stands for Strengths-Weaknesses-Opportunities-Threats. The aim is for the project team to construct a 2 x 2 matrix including each of the four areas.
Systematic sampling
Systematic sampling is a method used to obtain a regular sample from a population. It is used in Lean Six Sigma activities to obtain structured data based on time within a process. Systematic samples can be taken at a time interval (e.g. every 1 hour) or as part of a process flow (e.g. every 100 items or every 500 invoices).