Six Sigma

8 Dimensions of Quality

By Ron Pereira Updated on October 4th, 2022

8 Dimensions of Quality

The definition of quality is often a hotly debated topic. While it may seem intuitive, when we get right down to it, “quality” is a difficult concept to define with any precision.

The most fundamental definition of a quality product is one that meets the expectations of the customer. However, even this definition is too high level to be considered adequate.

In order to develop a more complete definition of quality, we must consider some of the key dimensions of a quality product or service.

Dimension 1: Performance

Does the product or service do what it is supposed to do, within its defined tolerances?

Performance is often a source of contention between customers and suppliers, particularly when deliverables are not adequately defined within specifications.

The performance of a product often influences the profitability or reputation of the end-user. As such, many contracts or specifications include damages related to inadequate performance.

Dimension 2: Features

Does the product or services possess all of the features specified, or required for its intended purpose?

While this dimension may seem obvious, performance specifications rarely define the features required in a product. Thus, it’s important that suppliers designing products or services from performance specifications are familiar with their intended uses, and maintain close relationships with the end-users.

Dimension 3: Reliability

Will the product consistently perform within specifications?

Reliability may be closely related to performance. For instance, a product specification may define parameters for up-time or acceptable failure rates.

Reliability is a major contributor to brand or company image and is considered a fundamental dimension of quality by most end-users.

Dimension 4: Conformance

Does the product or service conform to the specification?

If it’s developed based on a performance specification, does it perform as specified? If it’s developed based on a design specification, does it possess all of the features defined?

Dimension 5: Durability

How long will the product perform or last, and under what conditions?

Durability is closely related to warranty. Requirements for product durability are often included within procurement contracts and specifications.

For instance, fighter aircraft procured to operate from aircraft carriers include design criteria intended to improve their durability in the demanding naval environment.

Dimension 6: Serviceability

Is the product relatively easy to maintain and repair?

As end users become more focused on the Total Cost of Ownership than simple procurement costs, serviceability (as well as reliability) is becoming an increasingly important dimension of quality and criteria for product selection.

Dimension 7: Aesthetics

The way a product looks is important to end-users. The aesthetic properties of a product contribute to a company’s or brand’s identity. Faults or defects in a product that diminish its aesthetic properties, even those that do not reduce or alter other dimensions of quality, are often causes for rejection.

Dimension 8: Perception

Perception is reality. The product or service may possess adequate or even superior dimensions of quality but still fall victim to negative customer or public perceptions.

As an example, a high-quality product may get a reputation for being low quality based on poor service by installation or field technicians. If the product is not installed or maintained properly and fails as a result, the failure is often associated with the product’s quality rather than the quality of the service it receives.


It should be obvious from the discussion above that the individual dimensions of quality are not necessarily distinct. Depending on the industry, situation, and type of contract or specification several or all of the above dimensions may be interdependent.

When designing, developing, or manufacturing a product (or delivering a service) the interactions between the dimensions of quality must be understood and taken into account.

While these dimensions may not constitute a complete list of relevant dimensions, taking them into consideration should provide us with a better understanding of the slippery concept of quality.

What other dimensions can you think of?

Learn More

If you’re interested in learning much more about quality and other problem-solving tools please be sure to explore Gemba Academy’s School of Six Sigma where we now offer more than 200, highly engaging, training videos.

We also offer formal Green, Black, and Master Black Belt Certification for those interested.

  1. Tiffanyfr

    May 22, 2009 - 10:02 pm

    I think another dimension of quality is:
    *Safety: i.e. how safe the products are for its users. For eg; air bags,etc

  2. Maria

    January 22, 2010 - 12:41 pm

    Quality is extremely important in every stage, focusing in quality helped my company to reduce cost on long term basis.

  3. Spencer

    September 29, 2010 - 11:19 am

    I’ve come across four additional dimensions of quality, including time, human-to-human-interface and uniformity. It seems to me that time and human-to-human interface should add to the above traditionally known eight dimensions.

  4. Ben

    September 11, 2011 - 3:21 am

    hi!!!!! i think SATISFACTION could be an added dimension….

  5. venkata snc peesapati

    July 21, 2014 - 10:57 pm

    The eight dimensions cover all aspects of quality. For, example, safety is also part of performance as it is expected out of the product . One should try to like every other thing of quality to these eight dimensions.

  6. Jeyaprakash R

    February 22, 2022 - 5:11 pm

    In my opinion all of your requirements covered in these 8 dimensions

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