# Quality, Reliability and Value Flashcards

What is QFD (Quality Function Deployment)?

Quality function deployment (QFD) is a method developed in Japan beginning in 1966 to help transform the voice of the customer into engineering characteristics for a product. (quality is a measure of customer satisfaction with a product or a service)

What are the 6 related matrices in the house of quality used in QFD?

- Customer attributes
- Engineering characteristics
- Relationships
- Technical matrix
- Technical correlations
- Planning matrix

What is in the customer attributes matrix

Structure list of consumer wants and needs, determined by market research , along with a priority quantitative value.

What’s in the Engineering characteristics matrix?

Matrix of how the wants may be achieved, in general/not solution specific terms, representing the voice of the designer, can be quantified eg. weight, size, battery life…

What’s in the relationships matrix?

To what extent does the Engineering characteristic contribute to meeting the consumer attributes. Can be signified by symbols representing Strong relationship, moderate relationship, weak relationship (nothing = no relationship)

What’s in the technical matrix?

Calculates a numerical value for each engineering characteristic so that the characteristics that have the greatest impact on consumer satisfaction can be identified. (multiply the priority of the consumer attribute by the strength of the relationship that the EC has)

What’s in the technical correlations matrix?

TCs are the ‘roof’ of the house of quality, it correlates the engineering characteristics that have an influence on one another, with different symbols for different strengths of positive/negative correlations.

What’s in the planning matrix?

Quantitative market data comparing consumer satisfaction levels. Looks at consumer attributes and quantifies how well the need is currently met my existing competitor products, can be scored on 1-5 scale where 5 represents a need that is met v well currently.

What is QFD useful for?

As a method to structure product planning and design, relating customer needs to technical characteristics. it exists in the intersection f quality assurance, quality control and value engineering

Why is reliability engineering important?

All physical components eventually fail so it isi important to estimate the probability of component or system failure as a function of time, which is done by calculating the reliability function.

What is a series topology?

Means all components must work satisfactorily for the system to function correctly (Therefore reliability of series topology is the product of all the individual reliabilities)

What is a parallel topology?

Means all components must fail for the system to fail (therefore the probability of failure is the product of all the individual failure probabilities)

What is the equation for component reliability?

1 - Probability of failure

What does the reliability function model?

The probability of no failure before time t

What 3 curves sum to give the ‘bathtub curve’ of observed failure rate with time?

Constant/random failures

Early “infant mortality” failure

Wear out failures