Notable approaches to quality control
There is a tendency for individual consultants and organizations to name their own unique approaches to quality control—a few of these have ended up in widespread use:
Terminology | Approximate year of first use | Description |
---|---|---|
Statistical quality control (SQC) | 1930s | The application of statistical methods (specifically control charts and acceptance sampling) to quality control.[4]:556 |
Total quality control (TQC) | 1956 | Popularized by Armand V. Feigenbaum in a Harvard Business Review article[5] and book of the same name.Stresses involvement of departments in addition to production (e.g., accounting, design, finance, human resources, marketing, purchasing, sales). |
Statistical process control(SPC) | 1960s | The use of control charts to monitor an individual industrial process and feed back performance to the operators responsible for that process. Inspired by control systems. |
Company-wide quality control (CWQC) | 1968 | Japanese-style total quality control[6] |
Total Quality Management(TQM) | 1985 | Quality movement originating in the United States Department of Defense that uses (in part) the techniques of statistical quality control to drive continuous organizational improvement.[7] |
Six Sigma (6σ) | 1986 | Statistical quality control applied to business strategy.[8] Originated by Motorola. |
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WHAT IS OPERATIONS RESEARCH?
WHAT IS OPERATIONS RESEARCH?
A
common misconception held by many is that O.R. is a collection of mathematical tools. While it is true that it uses a variety of
mathematical techniques, operations research has a much broader scope. It is in fact a systematic approach to
solving problems, which uses one or more analytical tools in the process of
analysis. Perhaps the single biggest
problem with O.R. is its name; to a layperson, the term “operations research”
does not conjure up any sort of meaningful image! This is an unfortunate consequence of the
fact that the name that A. P. Rowe is credited with first assigning to the
field was somehow never altered to something that is more indicative of the
things that O.R. actually does.
Sometimes O.R. is referred to as Management Science (M.S.) in order to
better reflect its role as a scientific approach to solving management
problems, but it appears that this terminology is more popular with business
professionals and people still quibble about the differences between O.R. and
M.S. Compounding this issue is the fact
that there is no clear consensus on a formal definition for O.R. For instance, C. W. Churchman who is
considered one of the pioneers of O.R. defined it as the application of scientific methods, techniques and tools to problems
involving the operations of a system so as to provide those in control of the
system with optimum solutions to problems.
This is indeed a rather comprehensive definition, but there are many
others who tend to go over to the other extreme and define operations research
to be that which operations researchers
do (a definition that seems to be most often attributed to E. Naddor)! Regardless of the exact words used, it is
probably safe to say that the moniker “operations research” is here to stay and
it is therefore important to understand that in essence, O.R. may simply be
viewed as a systematic and analytical
approach to decision-making and problem-solving. The key here is that O.R. uses a methodology
that is objective and clearly articulated, and is built around the philosophy
that such an approach is superior to one that is based purely on subjectivity
and the opinion of “experts,” in that it will lead to better and more
consistent decisions. However, O.R. does
not preclude the use of human
judgement or non-quantifiable reasoning; rather, the latter are viewed as being
complementary to the analytical approach.
One should thus view O.R. not as an absolute decision making process,
but as an aid to making good
decisions. O.R. plays an advisory role
by presenting a manager or a decision-maker with a set of sound, scientifically
derived alternatives. However, the final
decision is always left to the human being who has knowledge that cannot be
exactly quantified, and who can temper the results of the analysis to arrive at
a sensible decision.
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Paradise (part 2 of 2)
The Joys of Paradise
Those who enter Paradise will do so in their most perfect, beautiful form. Their hearts will be one. They will neither spit, nor blow their noses, or defecate. They will remain young forever, strong and potent without the inconveniences of body hair.
The worldly pleasures pretty much fade in the face of heavenly delights. The pleasures of this world are fleeting and short-lived, for ‘…short is the enjoyment of this world,’ whereas the joys of Paradise will be unending, as ‘…the provision is eternal.’
The fine clothes, delicious foods, soothing drinks, ornate jewels, and grand palaces in Paradise are far superior to what is in this world. The ‘real estate’ of Paradise is described by the Prophet to be better than the whole world!
Paradise is free of any pollutants, foul odors, pain, or discomfort. The hearts and speech will be pure. No one will be offended or insulted.
The delicious, ripe fruits of Paradise will be within easy reach, ready for its residents to pick whatever fruit one desires. Any food or drink will be available on demand. Paradise has seas of water, wine, milk, and honey from which rivers will flow out. You simply take your pick! It has fountains scented with camphor and ginger, and shady valleys. The wine will not cause hangovers. It is “delight for those who drink”, bringing neither drunkenness[1] nor rousing folly or quarrelling.
The inhabitants of Paradise will be served in gold and silver goblets and dishes. Their finest silk clothes will be decorated with gold, silver, and pearls…better than any man-made garment! The scent of Musk will emanate from their bodies.. Their palaces will distinguished by refined elegance and be fully furnished. They will be able to sit and recline in their gardens. The beautiful bright colored couches will be lined with silk brocade. Eye catching cushions and splendid carpets will add style and luxury. A cozy place most people can simply dream of in this world, and tranquil spot away from distractions; peaceful, comfortable, and richly decorated.
The faithful, who ‘will be served by immortal youths, with cups, and jugs, and a glass from the flowing wine;’ exquisite banquets served in priceless vessels.
The faithful will visit one another and reunite with family and friends who made it to Paradise. All wishes will be fulfilled, some in the strangest ways. The Messenger of Allah said:
“If the believer in Paradise wishes for a child, it will be conceived and delivered, and will grow to the desired age in an instant.” (Al-Tirmidhi)
Naturally, running after worldly pleasures at the cost of heavenly delights will be a cause of much sorrow for people who will enter Hell.
Spouses & Intimacy in Paradise
Just as some people can’t perceive colors, so we may be soul-blind and soul-deaf. The soul’s yearnings simply don’t get through to consciousness; or if they do, we try to numb ourselves to them with medications or frenzied activities. The resulting alienation within our very hearts bears its own loneliness. The soul wants to be attached and involved, because it is through such intimacy that it is nourished, initiated, and deepened. The faithful will enjoy earthly and heavenly spouses in Paradise to satisfy the soul’s cravings for companionship and intimacy. All the urgencies of the soul – the feeling of longing, the ache of desire for a beautiful, compatible partner, and the urgency to visit old friends – will be met. The select will rejoice in the company of the parents, spouses and children who were believers.
The faithful will be clothed in the richest silks and brocades, and adorned with bracelets of gold and silver, and crowns set with pearls, and will make use of silken carpets, couches, and pillows. In order to enjoy all these pleasures, Allah will grant them perpetual youth, beauty, and vigor. There is a hadeeth which states that they will enter Paradise “aged thirty-three years.” It is the most perfect age at which one is most able to enjoy physical pleasures, and the age at which one’s health and strength are most perfect. It is proven from the Prophet they “will never lose their youth.”
The faithful will enter Paradise in the best and most perfect condition in all senses. They will remain young forever, their eternal delight will be unending, and they will live a life of unspoiled joy.
The faithful will enjoy specially crafted maidens, or houris, of Paradise, created not of clay, as in the case of mortal women, but of pure musk, and free from all natural impurities, defects, and inconveniences. They will be beautiful, modest, and secluded from public view in pavilions of hollow pearls. Thus the body will have its share of gratification.
Vision of Allah
In heaven the faithful will see Allah, clearly and distinctly. Here on earth we “see” Him but indirectly through the mirror of creation.
In Paradise, no creature will stand between Allah and the faithful who will delight in His glimpse. The most wonderful melody of all will be the voice of Allah greeting the select.
Since in beholding Allah face to face the faithful will find perfect happiness and ultimate delight, the vision may be called “beatific”. The joy of looking at Him will be greater than any other joy of Paradise, the rivers, palaces, tents of pearl, the pure spouses or the food and drink. All other joys will pale in comparison to the joy of looking at the most beautiful Face of Allah.
He says:
“Some faces that Day shall be radiant looking at their Lord.” (Quran 75:22-23)
So the faces of the faithful will also radiate and become beautiful with His Light.
The Prophet said:
“When the people of Paradise enter Paradise, Allah will say, ‘Do you want anything more?’ They will say, ‘Have You not brightened our faces, admitted us to Paradise and saved us from Hell?’ Then the veil will be lifted and they will not have seen anything more dear to them than looking upon their Lord, may He be glorified and exalted. This is what is meant by ‘even more.’” Then he recited the verse:
“For those who have done good is the best reward and even more (i.e. having the honor of glancing at the Countenance of Allah)” (Quran 10:26)
Once you know that the people of Paradise will not be given anything dearer than looking upon the Face of their Lord, imagine the deprivation of the sinners described by Allah:
“Nay! Surely, they (evil doers) will be veiled from seeing their Lord that Day” (Quran 83:15)
People said: “O Messenger of Allah, will we see our Lord on the Day of Resurrection?” The Messenger of Allah, may Allah praise him, said: “Do you doubt that you see the moon on the night when it is full?” They said, “No, O Messenger of Allah.” He said, ‘Do you doubt that you see the sun when there is no cloud?” They said, “No, O Messenger of Allah.” He said, “You will see Him likewise…”
Let us pray to Allah to keep us steadfast in this life and to grant us Paradise from His mercy in the life to come and to grant us His vision.
Footnotes:
[1] Non-intoxicating, as mentioned in Quran 56:19. There will be no need for intoxication in Paradise, as we will be in the highest state of pleasure.
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PREHISTORY
Evidence of the early human occupation of Algeria
is demonstrated by the discovery of 1.8 million year old Oldowan stone
tools found at Ain Hanech in 1992. In 1954
fossilised Homo erectus bones were discovered by C. Arambourg at
Ternefine that are 700,000 years old. Neolithic civilization
(marked by animal domestication and subsistence
agriculture) developed in the Saharan and Mediterranean Maghrib
between 6000 and 2000 BC. This type of economy, richly depicted in the Tassili
n'Ajjer cave
paintings in southeastern Algeria, predominated in the
Maghrib until the classical period. The amalgam of peoples of North Africa
coalesced eventually into a distinct native population, the Berbers lacked a
written language and hence tended to be overlooked or marginalized in
historical accounts.
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SOFTWARE
Software
In the late '70's the Centre de Geostatistique, Fountainebleau, began a master level program in geostatistics (two years) which attracted a steady stream of students from industry and goverment in various countries. In cooperation with Shell Oil and the Bureau de Recherche Geologie Mathematique (the French USGS), a commercial software package called BLUEPACK was developed. The early version was only ported to the VAX but the successor, ISATIS, is available on a number of workstation platforms. It is marketed in the US by GEOMATH of Houston. Geostatistics without the computer is of little interest, in many ways the developments in geostatistics parallel those in computing, particularly the appearance of PC's and workstations.
Publications and Conferences
Two small volumes on geostatistics focused on mining appeared in English in the 70's, one by Jean-Michel Rendu and one by Isabel Clark. In the late '80's the volume by Isaaks and Srivastava appeared, subsequently a book by Noel Cressie (on the more general topic of spatial statistics but including geostatistics).
In the summer of 1983 a second NATO ASI was held at Lake Tahoe, NV with a more international mix and including researchers from a wider set of applications. Thanks to a series of four papers by Richard Webster and some of his students (then at Rothamstead Research Center in England), geostatistics became known in the soil sciences. These appeared in the J. Soil Science (1980-1981). In 1979 in Prague, the International Association of Mathematical Geologists was founded and later began publishing the J. of the Int. Assn. Math. Geologists (later the name was officially changed to simply Mathematical Geology). While the journal was not limited to geostatistics it quickly became a principal place to publish such papers. A third international geostatistics congress was held in Avignon, France in 1988, a fourth in Troia, Portugal in 1992 and the most recent in Wollongong, Australia in 1996. Following the 1983 conference, Andre Journel and Leon Borgman (University of Wyoming) proposed an annual summer retreat in geostatistics aimed at researchers in North America. The first one was held near DuBois, Wyoming in August of 1984. The group was small and families were encouraged, the sessions were informal and no proceedings were produced but subsequently a newsletter was started which has appeared infrequently since then. A non-organization was founded in 1987 at a meeting in the Chirachaua Mtns southeast of Tucson, there were to be no dues, no membership list, no subscription price for the newsletter but volunteers would be solicited each year to organize meetings. Several have been held in Canada as well as the US and in 1996 a meeting was held in Guanajuato, MX. Following the establishment of the newsletter in North America another newsletter intended for the European community was established.
Following the 1983 meeting several staff members at EPA-Las Vegas became interested in the application of geostatistics to environmental monitoring and assessment. In addition to research support for a number of individuals and programs, EPA commissioned a geostatistical software package, GEO-EAS, which was then released into the public domain. GEO-EAS was a DOS program but included a menuing system that made it fairly friendly and the price was right. Unfortunately for various reasons EPA has not continued to support the software and it has not been updated for a number of years. In 1992 Andre Journel and Clayton Deutsch published GSLIB which included a floppy disk. This was an extensive set of geostatistical programs (FORTRAN source code) and a users manual. Current versions of the code are available on the website at Stanford. Unfortunately the programs did not include any form of GUI and are intended to be run in batch mode. They are compilable on a variety of platforms however. In 1996 Yvan Pannatier published VARIOWIN together with a floppy disk. VARIOWIN is a MS-Windows version of two of the components of GEO-EAS. It allows for much larger data sets than in GEO-EAS and also interactive variogram modeling.
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DATA
The Nature of Data and Variation
Although natural phenomena in the real life are unpredictable, the designs of experiments are bounded to generate data that varies because of intrinsic (internal to the system) or extrinsic (due to the ambient environment) effects. How many natural processes or phenomena in the real life that have an exact mathematical closed-form description and are completely deterministic can we describe? How do we model the rest of the processes that are unpredictable and have random characteristics?
Uses and Abuses of Statistics
Statistics is the science of variation, randomness and chance. As such, statistics is different from other sciences, where the processes being studied obey exact deterministic mathematical laws. Statistics provides quantitative inference represented as long-time probability values, confidence or prediction intervals, odds, chances, etc., which may ultimately be subjected to varyious interpretations. The phrase Uses and Abuses of Statistics refers to the notion that in some cases statistical results may be used as evidence to seemingly opposite theses. However, most of the time, common principles of logic allow us to disambiguate the obtained statistical inference.
Design of Experiments
Design of experiments is the blueprint for planning a study or experiment, performing the data collection protocol and controlling the study parameters for accuracy and consistency. Data, or information, is typically collected in regard to a specific process or phenomenon being studied to investigate the effects of some controlled variables (independent variables or predictors) on other observed measurements (responses or dependent variables). Both types of variables are associated with specific observational units (living beings, components, objects, materials, etc.)
Statistics with Tools (Calculators and Computers)
All methods for data analysis, understanding or visualizing are based on models that often have compact analytical representations (e.g., formulas, symbolic equations, etc.) Models are used to study processes theoretically. Empirical validations of the utility of models are achieved by inputting data and executing tests of the models. This validation step may be done manually, by computing the model prediction or model inference from recorded measurements. This process may be possibly done by hand, but only for small numbers of observations (<10). In practice, we write (or use existent) algorithms and computer programs that automate these calculations for greater efficiency, accuracy and consistency in applying models to larger datasets.
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INTRODUCTION TO DATA ANALYSIS-PART 2 -
Final stage of the initial data analysis
During the final stage, the findings of the initial data analysis are documented, and necessary, preferable, and possible corrective actions are taken.
Also, the original plan for the main data analyses can and should be specified in more detail and/or rewritten.
In order to do this, several decisions about the main data analyses can and should be made:
- In the case of non-normals: should one transform variables; make variables categorical (ordinal/dichotomous); adapt the analysis method?
- In the case of missing data: should one neglect or impute the missing data; which imputation technique should be used?
- In the case of outliers: should one use robust analysis techniques?
- In case items do not fit the scale: should one adapt the measurement instrument by omitting items, or rather ensure comparability with other (uses of the) measurement instrument(s)?
- In the case of (too) small subgroups: should one drop the hypothesis about inter-group differences, or use small sample techniques, like exact tests orbootstrapping?
- In case the randomization procedure seems to be defective: can and should one calculate propensity scores and include them as covariates in the main analyses?[11]
Analyses
Several analyses can be used during the initial data analysis phase:
- Univariate statistics (single variable)
- Bivariate associations (correlations)
- Graphical techniques (scatter plots)
It is important to take the measurement levels of the variables into account for the analyses, as special statistical techniques are available for each level:
- Nominal and ordinal variables
- Frequency counts (numbers and percentages)
- Associations
- circumambulations (crosstabulations)
- hierarchical loglinear analysis (restricted to a maximum of 8 variables)
- loglinear analysis (to identify relevant/important variables and possible confounders)
- Exact tests or bootstrapping (in case subgroups are small)
- Computation of new variables
- Continuous variables
- Distribution
- Statistics (M, SD, variance, skewness, kurtosis)
- Stem-and-leaf displays
- Box plots
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Scope and training programs
Almost all educational programmes in biostatistics are at postgraduate level. They are most often found in schools of public health, affiliated with schools of medicine, forestry, or agriculture, or as a focus of application in departments of statistics.
In the United States, where several universities have dedicated biostatistics departments, many other top-tier universities integrate biostatistics faculty into statistics or other departments, such as epidemiology. Thus, departments carrying the name "biostatistics" may exist under quite different structures. For instance, relatively new biostatistics departments have been founded with a focus on bioinformatics and computational biology, whereas older departments, typically affiliated with schools of public health, will have more traditional lines of research involving epidemiological studies and clinical trialsas well as bioinformatics. In larger universities where both a statistics and a biostatistics department exist, the degree of integration between the two departments may range from the bare minimum to very close collaboration. In general, the difference between a statistics program and a biostatistics program is twofold: (i) statistics departments will often host theoretical/methodological research which are less common in biostatistics programs and (ii) statistics departments have lines of research that may include biomedical applications but also other areas such as industry (quality control), business andeconomics and biological areas other than medicine.
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STATISTICIAN
A statistician is someone who works with theoretical or applied statistics. The profession exists in both the private and public sectors. It is common to combine statistical knowledge with expertise in other subjects.
According to the United States Bureau of Labor Statistics, as of 2010, 25,100 jobs were classified as statistician in the United States. Of these people, approximately 30 percent worked for governments (federal, state, or local). Additionally, there is a substantial number of people who use statistics in their work but have job titles other than statistician, such as actuaries, applied mathematicians, economists, financial analysts, psychometricians, epidemiologists, and quantitative psychologists. The job of statistician is considered a profession. Most statisticians work in offices and have regular working hours and can therefore be considered white-collar workers. A minority of statisticians are self-employed statistical consultants.[citation needed]
Most employment as a statistician requires a minimum of a masters degree in statistics or a related field. Many professional statisticians have a PhD. Typical work includes collaborating with scientists, providing mathematical modeling, simulations, designing randomized experiments and randomized sampling plans, analyzing experimental or survey results, and forecasting future events (such as sales of a product).
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SURVEY METHODOLOGY -INTRODUCTION 1-
A field of applied statistics, survey methodology studies the sampling of individual units from a population and the associated survey data collection techniques, such as questionnaire construction and methods for improving the number and accuracy of responses to surveys.
Statistical surveys are undertaken with a view towards making statistical inferences about the population being studied, and this depends strongly on the survey questions used. Polls aboutpublic opinion, public health surveys, market research surveys, government surveys and censuses are all examples of quantitative research that use contemporary survey methodology to answers questions about a population. Although censuses do not include a "sample", they do include other aspects of survey methodology, like questionnaires, interviewers, and nonresponse follow-up techniques. Surveys provide important information for all kinds of public information and research fields, e.g., marketing research, psychology, health professionals and sociology
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