A Brief History of Quality: Approaches to Quality

Organisations have continually looked for new ways to improve consistency and quality in their products and services. Management fads may come and go but many of the underlying ideas around quality remain the same. Here's how the works of Deming, Juran and Crosby remain at the heart of quality approaches like TQM and Six Sigma.

Editor's note: you can find out more about the theories of Deming, Juran and Crosby in A Brief History of Quality: How the Concept of Quality has Evolved, published earlier this week.

Total Quality Management

Deming's views on quality are believed by many to have laid the foundations for Total Quality Management (TQM), however, the works of Feigenbaum, Ishikawa and Imai have also had an impact.

TQM focuses on achieving quality through engraining the philosophy within an organisation, although it does not form a system or a set of tools through which to achieve this.

Companies adopting a TQM philosophy should see their competitiveness increase, establish a culture of growth, offer a productive and successful working environment, cut stress and waste and build teams and partnerships, according to the Chartered Quality Institute.

The principles of TQM have been laid out in the ISO 9000 family of standards from the International Organization for Standardization. Adopted by over one million companies in 176 countries worldwide, the standards lay down the requirements of a quality management system, but not how these should be met.

Eight principles make up the ISO 9000 standards. These are:

  • Organisations should be consumer focused by understanding their needs and meeting their requirements
  • Strong leadership should ensure the organisation understands its purpose and direction
  • People at all levels should be involved in the quality process for the organisation to reap the greatest benefit
  • A process approach should be taken to activities and any related resources
  • Interrelated processes should be identified as a system to boost efficiency in meeting objectives
  • Organisations should strive for continual improvement
  • Decisions should be based on factual information
  • A mutually beneficial relationship should be created between organisations and suppliers

But standards alone are not often not enough for companies to reach their quality goals, hence the development of more structured processes like six sigma.

Six Sigma

Whereas TQM is a philosophy of quality, Six Sigma is a definitive measurement of quality – or at least that's how it started.

Motorola pioneered six sigma over two decades ago and in this time it has evolved from a simple metric – 3.4 defects per one million opportunities – which was often applied to manufacturing, to a methodology and management system adopted by numerous business sectors.

By aiming for 3.4 defects it diverges from the zero-deficits model proposed by Crosby, which many see as unattainable and in some cases demotivating.

As Deming said in his 14 principles of quality management, companies should "eliminate slogans, exhortations, and targets for the workforce asking for zero defects and new levels of productivity.

"Such exhortations only create adversarial relationships, as the bulk of the causes of low quality and low productivity belong to the system and thus lie beyond the power of the work force."

Sitting at the heart of the Six Sigma philosophy is the DMAIC model for process improvement; define opportunity, measure performance, analyse opportunity, improve performance, control performance.

Alternatively the DMADV (define, measure, analyse, design, verify) system is used for the creation of new processes which fit with the six sigma principles.

Motorola believes that even combining the methodology and the metric is "still not enough to drive desired breakthrough improvements and results that are sustainable over time", and therefore advocates the use of the six sigma management system, which aligns management strategy with improvement efforts.

Companies which have successfully implemented six sigma, such as GE, have reported savings running into millions of dollars and six sigma is now being combined with lean manufacturing processes to great effect.

But it is highly unlikely any of these interpretations present the end goal for quality management, which as the methodologies teach, must always strive for continuous improvement.