iSixSigma

Quality Attribute

Definition of Quality Attribute:

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A quality attribute is a characteristic of a system that is used to evaluate the system’s performance from the perspective of the end user. Determining the right set of characteristics to assess a system’s performance is the first step in quality control and management. The quality attributes must then be measured, monitored, managed, and improved to ensure a high-quality standard is consistently met.

Overview: What is a quality attribute?

Quality attributes are properties of a system that are measured to establish the overall system quality. They should be identified from a stakeholder’s perspective using a qualitative statement about the fitness of the system to perform its stated functions. The identified attributes are then translated into quantitative specifications of the system that can be measured. The importance of each quality attribute to the functionality of the system should then be assessed. Since many attributes are interrelated within a system, changes in one attribute may positively or negatively affect another attribute. These interdependencies are identified during trade-off analysis.

A critical to quality (CTQ) tree is a diagram based Six Sigma tool that helps identify the characteristics that are critical to quality from a customer’s perspective. Constructing a CTQ tree helps identify the attributes likely to drive quality and the best approach to meet them.

3 benefits of defining quality attributes

The quality of a product or service is not determined by the cost or effort that a business puts into delivering it; quality is determined by the benefit a customer derives from the product or service. A business is compensated based on the customers perspective of quality, and this should be the driving factor for any process improvement project.

Ensures quality targets align with customer expectations

By designing a quality management system based on customer identified quality attributes, a business can ensure that customer expectations drive quality.

Quality enhances the user experience

A focus on stakeholder-identified quality attributes throughout the lifetime of a product or service can provide benefits to stakeholders by promoting the development of new versions that incorporate elements providing user-focused functionality.

Builds brand value

Earnest effort in identifying a product’s or service’s most important quality attributes and developing a robust quality program around them can payoff significantly in terms of a reputation for meeting and exceeding customers’ expectations on a continuous basis.

Why are quality attributes important to understand?

Assigning the right attributes to define quality is critical in the establishment of an effective quality management system. A well implemented quality management system is critical to cost efficiency and the smart utilization of resources.

1. Greater customer satisfaction

At the onset of any process improvement project, a business should determine what attributes of the product or service are most important to their stakeholders. Meeting these needs should be at the heart of every business decision. Identifying the attributes that define quality helps a business translate the qualitative needs of its customers into specific, actionable, quantitative performance metrics.

2. Helps prioritize the most critical aspects of quality

After identifying the quality attributes that will define the quality of a product or service, they should be ordered in terms their importance to stakeholders. This order should have a strong influence on the amount of resources allocated to each attribute. During trade-off analysis, the interdependencies between quality attributes are identified to predicate complications that could arise during quality improvement.

3. Greater quality

Identifying and defining the most important quality attributes helps to focus the efforts of an organization on achieving its quality goals.

An industry example of a quality attribute

Quality is vital to optimizing customer satisfaction. Quality can also help in mitigating risk and protecting a company’s brand.

A prime example is the 2015 emissions cheating scandal at Volkswagen.

As an automobile manufacturer, emissions should be a focal point of quality management at Volkswagen. Volkswagen had coded computers in several diesel models to identify when the automobiles were being tested under laboratory conditions for compliance with emissions standards. During emissions testing, the computer would reduce fuel consumption, resulting in lower emissions of regulated nitrogen oxides, but under normal driving conditions, the automobiles would consume fuel in a manner that optimized fuel efficiency and performance at the cost of nearly 40x higher emissions.

If the attributes of fuel efficiency, performance, and complaint emissions would have been identified, prioritized by importance, and scrutinized through trade-off analysis, management would have concluded that emissions compliance could not be sacrificed to optimize fuel economy and performance. This would have saved the company nearly $35 billion in costs related to fines and recalls in addition to the considerable damage the scandal had on the company’s brand.

5 key steps in determining quality attributes

To provide a quality product or service, businesses must identify what attributes drive the user experience and how to translate those attributes into measurable performance requirements. To ensure that a quality management system translates into high quality, the attributes that will define quality must be carefully considered throughout a process improvement project.

1. Identify and prioritize each quality attribute

These will be determined from the viewpoint of the end user. Imagine the user experience and the expectations the user has of the product or service being offered. Prioritize the potential attributes according to their overall impact on the user experience.

2. Determine metrics that define each attribute

A metric or measurable value must be determined that will be used to assess each quality attribute. Product attributes will rely on easily quantified physical characteristics that are intuitive to measure. Service attributes are typically non-numeric and are more subjective such as dependability, availability, and usability.

3. Establish a method for measuring and monitoring these metrics

The method used to measure quality attributes must be well defined, accurate, and easily replicated. The tools, processes, and procedures used for measuring should be devised so that they can be incorporated into an ongoing quality management system that is robust enough for the environment it will be used in.

4. Collect, validate, and analyze measurements

Following the defined methods in step 3, data will be collected over a period of time on the quality of the systems. Specifications for validating these measurements should be established. Following validation, the data will be analyzed to understand the current level of quality being reached.

5. Establish quality guidelines for achieving high quality

The results of the analysis will provide a quantitative measure of quality under current operational conditions. Based on the capabilities of the organization, business needs, and customer expectations, quality goals will be set to guide the direction of the company.

Frequently Asked Questions (FAQ) about quality attributes

1. Why is trade-off analysis necessary?

Trade-off analysis is the assessment of interdependencies between the quality attributes of a system. Trade-off analysis is highly useful for predicting potential complications or problems that could arise during quality improvement efforts. With this understanding, high quality can be realized by the quantitative evaluation and precise trade off of multiple attributes.

2. How is the data from quality measurements utilized?

Control strategies including change management and deviation management define explicit values that define the overall quality of a product or service and are used to assess individual measurements. Storing these measurements in a centralized database is useful for generating a risk management system.

3. What is the role of quality attributes in quality by design?

The quality by design (QbD) approach defines the required level of quality in a final product at the beginning of the design phase by identifying product and in-process attributes that will be monitored to assess quality. The insight gained by continuous monitoring of these attributes is used to build quality into the manufacturing process and provides a basis for continuous improvement of both products and processes.

Quality is a measure of a system’s quality attributes

The quality of a product or service is ensured by keeping key attributes within appropriate limits. This is achieved by continuous monitoring of quality attributes. Identifying which attributes of the product or service are most important to stakeholders ensures that the specified quality translates into customer satisfaction. To develop an effective quality management system, trade-off analysis must be performed to identifying any interdependencies between quality characteristics and avoid complications during quality improvement.

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