Before 1911: from the craftsman to the factoryUntil the Industrial Revolution, quality was a matter of self-control, carried out by the craftsmen themselves. In this phase, the craftsman did everything: designed the product, chose the materials, produced and sold it, keeping direct contact with customers. Small quantities of each product were made, and parts were fitted by hand. Inspection of the finished product, when it existed at all, was informal. In this phase, quality was synonymous with technical perfection.With the factories of the 19th century, production grew and was divided among many workers, but quality control still depended largely on each worker's skill and eye, under the supervision of a foreman.From 1911 to 1930: Taylorism and inspectionAt the beginning of the 20th century, with the advent of mass production and F. W. Taylor's Scientific Management (The Principles of Scientific Management, Harper & Brothers, New York, 1911), the practice of quality control changed considerably, even though the concept of quality remained that of technical perfection. Quality control became an activity separate from production.According to Taylor: "The inspector is responsible for the quality of the work, and both the workmen and speed bosses (who see that the proper cutting tools are used, that the work is properly driven, and that cuts are started in the right part of the piece) must see that the work is finished to suit him." In other words, the purpose of inspection was to separate good products from defective ones before they were shipped to the consumer.Inspection activities were more formally linked to quality control in 1922, with the publication of The Control of Quality in Manufacturing by G. S. Radford. For the first time, quality was seen as a distinct management responsibility and as an independent function.Besides separating quality control from production, the Taylorist philosophy placed a number of constraints on quality during manufacturing:Excessive division of labor meant that the worker, reduced to a small, repetitive task, lost sight of how his part of the work affected the final result in terms of product quality.Productivity as the absolute measure of competitiveness, together with standard times, forced production staff to work ever faster, without considering manufacturing quality.A line produces 1,000 parts a day and, at the end of the shift, an inspector separates the 40 defective ones, which are scrapped. According to the Taylorist logic described above, what is the main limitation of this model?Answer: It detects the defect after it has already been produced, without tackling the cause — final inspection separates good from bad, but the 40 parts (4%) keep being made every day. Separating good from bad is precisely what it does well.From the 1920s to the 1950s: statistics and samplingThe statistical turn began at Bell Telephone Laboratories in the United States. In 1924, Walter A. Shewhart proposed the control chart, which distinguishes the natural variation of a process (common causes) from variation that has a specific cause to be investigated (special causes). His ideas were gathered in the book Economic Control of Quality of Manufactured Product (1931) and gave rise to statistical process control (SPC).Also at Bell Labs, from the late 1920s, H. F. Dodge and H. G. Romig developed techniques for inspecting lots by sampling, based on probability: the quality of the lot is estimated from the quality of a sample. The tables were published as a book in 1944 (Sampling Inspection Tables: Single and Double Sampling; 2nd ed., Wiley, New York, 1959). These techniques greatly simplified inspection and made it more accurate, and during World War II they were adopted on a large scale in US military procurement.Sampling inspection gave rise to the concept of Acceptable Quality Level (AQL), enshrined in the military sampling standards of the 1940s (which led to MIL-STD-105, from 1950): a target expressed as a percentage of defective items, supposedly based on economic reasons. Today it is recognized that a devastating effect of this concept is that it promotes quality improvement up to a certain level, beyond which quality improvements are not economically justified. In other words, from this perspective, production scrap came to be seen as undesirable but inevitable. This thinking prevailed for many decades.Therefore, between the 1920s and the 1950s, while techniques evolved toward statistical process control (control charts) and sampling inspection, the concept of quality shifted from technical perfection to an acceptable quality level.A buyer accepts lots of screws with an AQL of 1%. He receives 50,000 screws a month and every lot is approved right at the limit of the plan. What is the modern criticism of this arrangement?Answer: It treats receiving about 500 defective screws a month as normal and creates no incentive to reach zero — 1% of 50,000 = 500. This is exactly the idea of scrap as undesirable but inevitable. AQL does not guarantee zero defects: it defines how many defects are accepted.From 1950 to 1970: Total Quality ControlFrom the 1950s onward, the concept of quality was radically revised, with the ideas of total quality brought by pioneers such as Deming, Juran, Feigenbaum and Ishikawa, today regarded as the quality gurus.The total quality philosophy took hold first in Japan, which would eventually revolutionize and frighten Western industry. The American economy was booming and therefore blind and deaf to these ideas. On the other side of the Pacific, the situation was very different: an industrial base devastated by the war and a reputation for poor-quality goods were holding back Japan's economic recovery.W. Edwards DemingIn 1950, at the invitation of JUSE (the Union of Japanese Scientists and Engineers), Deming went to Japan to give a series of lectures on statistical quality control. Finding an audience of top executives eager to get out of the crisis, he saw a favorable environment for putting his ideas into practice. In 1951, JUSE created the Deming Prize in his honor, still one of the most important awards in the field.W. Edwards DemingDeming advocates worker participation in decision-making and states that 94% of quality problems are the responsibility of management (they belong to the system), not of the workers, who are hampered by it. He urges top management to get involved in quality improvement programs. His set of commandments, consolidated in the book Out of the Crisis (1986; the first version, from 1982, was titled Quality, Productivity, and Competitive Position), became known as Deming's 14 Points:Create constancy of purpose toward improving products and services, with the aim of becoming competitive, staying in business and providing jobs. An organizational vision should guide the company and give it a goal.Adopt the new philosophy. Management must wake up to the challenge, take on its responsibilities and lead the change. High levels of delays, errors and defects can no longer be tolerated.Cease dependence on inspection to achieve quality. Quality must be built into the product from the start, with tools such as statistical process control. Inspection only measures the problem; it does not correct it.End the practice of awarding business on the basis of price alone. Seek to minimize total cost and move toward a single supplier for each item, in a long-term relationship of loyalty and trust.Improve every process constantly and forever. Find problems by working on the processes. As quality and productivity improve, costs go down. Do not fight fires: prevent defects and improve processes.Institute training on the job, at every level of the organization.Adopt and institute leadership. Leadership comes from knowledge, expertise and interpersonal skills, not from rank. Leaders remove the barriers that keep people from doing their best.Drive out fear, so that everyone can work effectively. Fear kills creativity, which is the engine of quality improvement, and it grows with insecurity, punishment and a culture of internal competition. It can be eliminated by overcoming failures in communication, culture and training.Break down barriers between departments. People in research, design, sales and production must work as a team to foresee problems in production, use and performance of the product or service.Eliminate slogans, exhortations and numerical targets that ask workers for zero defects without giving them the conditions and methods to get there. Such exhortations create friction, since most of the time the cause of low productivity and poor quality lies in the system.Eliminate numerical quotas and management by numbers. Managers should replace quotas with leadership based on knowledge of the work. Quotas ignore statistics: there is natural variation, and not every worker can be above average.Remove the barriers that rob people of pride and satisfaction in their work, such as annual merit rating systems and management by objectives.Institute a vigorous program of education and self-improvement. Training changes behavior in the short term; education produces effects in the long term.Create a structure so that everyone in the company puts the previous 13 points into practice. Top management must engage everyone in the work of transformation.It is important to note that Deming, like other total quality pioneers, realized that statistical tools only work with top management's long-term commitment to continuous improvement, with investment in training and education of people, and with changes in management methods.Armand V. FeigenbaumIn 1956, in an article in the Harvard Business Review, A. V. Feigenbaum argued that high-quality products had no chance of being made if the manufacturing department continued to work in isolation. In his words: "The underlying principle of this total quality view is that, to provide genuine effectiveness, control must start with the design of the product and end only when the product has been placed in the hands of a customer who remains satisfied... the first principle to recognize is that quality is everybody's job."Armand V. FeigenbaumFor Feigenbaum, quality is a corporate way of life, a way of managing the company through a systemic approach, involving every function in the quality process.He introduced the term Total Quality Control (TQC) in the United States in the 1950s; his book Total Quality Control dates from 1961. Feigenbaum's proposal stands out for seeking to integrate the company's activities: he sees the industrial cycle as the sequence of activities needed to take a product from concept to market. This cycle includes marketing, design, engineering, purchasing, manufacturing, inspection, packaging, shipping, installation and service, and quality is present at every one of these stages, as the figure shows:The four jobs of quality control along the industrial cycle, according to FeigenbaumThe cost of quality is present at all these stages and can be minimized through a total view of quality, managed at each of them. There must be specifications at every stage of production to ensure that customer requirements are met.Task-related training and motivation must be a commitment of the organization. Quality programs should not be set aside when demand increases or when something new catches top management's attention. Feigenbaum's quality improvement program is usually summarized in the 18 steps below:Definition of Total Quality Control as a system that integrates the quality development, maintenance and improvement efforts of the company's various groups, to satisfy the customer at the most economical levels.Control as a management tool, in 4 steps: a) setting quality standards; b) appraising conformance to these standards; c) acting when the standards are not met; d) planning for improvements in the standards.Integration of activities, coordinating them for customer satisfaction.Quality increases profit, since it improves customer satisfaction, reduces operating losses and service costs and optimizes the use of resources, lowering total costs.Quality breeds quality: when one supplier pursues quality, the others work to match or exceed the new standard.People have an impact on quality: it is people's actions that produce the greatest improvements.Total Quality Control applies to all products and services. Every department and every person must provide quality products and services to their customers.Quality covers the entire life cycle of the product or service: from the customer's specification to design, manufacturing, transport, installation and after-sales service.Control involves 4 kinds of job: new design control, incoming material control, product control and special process studies (the same as in the figure above).The Total Quality Control system controls the company's key activities in an integrated and continuous way, with documented technical and managerial procedures that coordinate people, machines and information to ensure customer satisfaction at economical costs.Total Quality programs improve design and product quality, reduce losses and operating costs, raise employee morale and reduce production bottlenecks.Quality costs are a means of measuring and optimizing Total Quality Control activities. They fall into 4 categories: prevention, appraisal, internal failure and external failure.Quality Control must be an organized program, with the responsibilities of every member of the company clearly defined.The quality function should be a facilitator, not a police officer: it should communicate results, bring in new techniques and facilitate activities, acting as an internal consultant.Continuous commitment to quality. The program is neither a temporary improvement nor a simple cost cut: it is continuous and long-term.Use of statistical tools. Statistics are one part of Total Quality Control, not the whole.Automation is not a panacea: it is complex and can be very difficult to implement. Before automating, one should check whether people are carrying out the activities in the best way.Quality control at the source. The quality of a product should be controlled by whoever makes it, who must have the necessary authority and freedom to do so.Joseph M. JuranAt the same time, two other total quality pioneers, Juran and Ishikawa, each in his own context, put forward their ideas on commitment to improving the quality of products and processes. Juran published the Quality Control Handbook in 1951 and, in 1954, also at JUSE's invitation, brought to Japan the idea that quality is a management responsibility.For Juran, quality is associated with satisfaction and dissatisfaction with a product. Satisfaction occurs when the product has superior performance or features; dissatisfaction, when there are deficiencies in the product or service. There are therefore two dimensions to the concept of quality: an external one, which considers consumers' needs, and an internal one, related to freedom from failures in making the product.Joseph M. JuranBased on these two dimensions, Juran defines quality as "fitness for use". Since internal and external customers may use the product in different ways, achieving quality means starting by understanding who the user will be and how and where the product will be used. For Juran, the company is a process made up of several stages, each acting as customer and supplier. So there are internal customers and suppliers that, linked together, form a chain. At each stage there are opportunities for improvement, achieved project by project, through a succession of small projects that can be suggested by managers, operators and quality specialists.Improvement projects are chosen using the Pareto principle, a term coined by Juran himself, to separate the vital few problems from the trivial many and direct efforts correctly. Another way to prioritize them is by the costs of poor quality, since money is the main language of management. That is why Juran argues that middle management must be able to translate the language of things into the language of money, and vice versa. This requires a cost classification system: internal and external failure costs, appraisal (inspection) costs and prevention costs.Classic cost of quality model: total cost has a minimum pointThe figure shows the classic model of the 1950s and 1960s: as quality of conformance increases, failure costs fall and appraisal and prevention costs rise, and total cost has a minimum before 100%. This model is consistent with the idea of an acceptable quality level. Later, Juran himself and other authors showed that, as prevention becomes cheaper (better processes, automation), the optimum moves close to 100% conformance.A factory recorded 200 defects in the month: 90 in welding, 60 in painting, 25 in packaging, 15 in labeling and 10 of other kinds. Following Juran's Pareto principle, where should it start, and what share of the defects does that address?Answer: Welding and painting, 75% of the defects — (90 + 60) / 200 = 150 / 200 = 75%. These are the vital few. Starting with the easy ones (labeling and others = 25 / 200 = 12.5%) feels like progress but barely touches the total.Kaoru IshikawaIshikawa's quality program was influenced by Deming and Juran. His contribution is a broad view of quality, an emphasis on its human side, the cause-and-effect diagram, the use of the 7 tools and quality control circles (QC circles), launched in Japan in 1962.Kaoru IshikawaHis view of quality stresses the importance of quickly perceiving and meeting market needs, fitness for use of products and services, and low process variability. Seeing the process as a set of causes that must be controlled to obtain good products and services, he developed the cause-and-effect diagram (also called the Ishikawa or fishbone diagram). Ishikawa (1993) classified statistical control techniques into 3 groups of increasing complexity.The first group is made up of the 7 basic tools, which everyone in the company should know and which, according to him, can be used to analyze and solve up to 90% of quality problems. In Ishikawa's original list they are: Pareto chart, cause-and-effect diagram, histogram, control chart, check sheet, scatter diagram and stratification. Many books replace stratification with the flowchart.The second group brings together intermediate statistical methods, for use by quality specialists and by some managers responsible for quality in their area. They require some knowledge of statistics but can be learned by managers. They include sampling inspection, statistical estimation and design of experiments.The last group consists of advanced statistical methods, for use by specialists and consultants, such as multivariate analysis and operations research techniques.Ishikawa (1993) believes that total quality implies everyone's participation and group work rather than individual work. This led him to create quality control circles, which should be part of a broader program. According to him, quality is not a miracle drug but a natural remedy, with long-term results. It starts with the consumer: understanding their needs, translating them into clear specifications and treating their complaints as a vital opportunity for improvement. His quality program is based on 6 points:Definition by top management of a policy in which quality comes first, earning consumer trust and increasing sales and profits in the long term.Consumer orientation: the company must produce products and services that meet the customer's needs and requirements.Removal of barriers between divisions and departments: the customers of each process must be clearly defined so that there is efficient communication between them, making it easier to identify problems and check satisfaction.Description of facts through data and use of statistical methods: facts must be expressed through precise data, analyzed with statistical methods.A management philosophy of respect for humanity, with standardization of processes and procedures and delegation of authority. Management must allow human potential to grow, give people authority and let everyone take part in quality control through QC circles (Quality Control Circles).Cross-functional management, breaking the company's vertical rigidity and helping it work across divisions and functions.Ishikawa sees quality in four aspects:quality in the strict sense: related to product attributes and freedom from defects;cost: related to costs and prices;delivery: related to quantities and deadlines;service: the support given to the customer after the sale.In other words, product quality, from the customer's point of view, incorporates the efficiency and quality of the production system responsible for it. The table below summarizes the change in mindset:Traditional viewNew viewProductivity and quality have conflicting goalsProductivity gains are achieved through quality improvementQuality is defined as conformance to specifications and standardsQuality is defined by meeting customer needsQuality is measured by the degree of nonconformanceQuality is measured by continuous improvement of processes and products and by customer satisfactionQuality is achieved through product inspectionQuality is determined in product planning and achieved through effective process controlSome defects are allowed when the product meets minimum quality standardsDefects are prevented through process control techniquesQuality is a separate function, focused on the production processQuality is part of every function, at every stage of the product life cycleSupplier relationships are not integrated and revolve around costSupplier relationships are long-term and quality-orientedA manager says: 'If the worker made a mistake, it is his fault; let's put one more inspector at the end of the line.' Which of Deming's 14 points does this attitude clash with most?Answer: Cease dependence on inspection to achieve quality — another inspector only measures the problem after it has happened. The statement also contradicts Deming's idea that 94% of problems belong to the system, not to the worker.Conclusions on the 1950–1970 periodThe work of these authors marks a change in the concept of quality, bringing it closer to consumer satisfaction and away from the view of "technical perfection" or "acceptable quality level". Their definitions of quality were practically the same and followed the same theme:Deming: product quality as maximum usefulness to the consumer;Feigenbaum: quality as the user's complete satisfaction;Juran: quality as meeting customer needs (fitness for use);Ishikawa: effective quality is the one that truly brings satisfaction to the consumer.In the following decades, these ideas would spread across the West under the name Total Quality Management (TQM) and give rise to management system standards such as ISO 9001.
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