Design of Experiment:

Design of experiments (DOE) or experimental design is the design of any information-gathering exercises where variation is present, whether under the full control of the experimenter or not.

In the design of experiments, the experimenter is often interested in the effect of some process or intervention (the "treatment") on some objects (the "experimental units"), which may be people, parts of people, groups of people, plants, animals, etc. Design of experiments is thus a discipline that has very broad application across all the natural and social sciences and engineering.A well–performed experiment may provide answers to questions such as:

What are the key factors in a process? At what settings would the process deliver acceptable performance? What are the key, main and interaction effects in the process? What settings would bring about less variation in the output?

Cost of Quality: “Cost of Quality is a measurement used for assessing the waste or loss from a defined process. “

Cost of Quality is usually measured in monetary terms, requiring all losses and waste to be converted to their liquidated cost equivalent, for example, staff hours lost or spent are converted to their dollar equivalent by multiplying the hourly rate for the staff by the hours spent. Cost of quality measurements can be used to identify the optimum for a process, that is, the best possible outcome from all operating modes, combinations and permutations of the current process.

Most Cost of Quality measurements utilize 4 categories of costs:

Internal failure costs are associated with internal losses before the product or service is supplied to the client, such as equipment breakdowns, scrap and productivity losses.

External failure costs occur outside of the process being analyzed. These costs are usually discovered by or affect third parties such as clients.

Preventive costs are associated with the prevention of future losses due to poor quality, like planning, scheduled maintenance and quality assurance.

Assessment or appraisal costs are those associated with measurement and assessment of a process.

References:http://en.wikipedia.org/wiki/Design_of_experimentshttp://asq.org/learn-about-quality/data-collection-analysis-tools/overview/design-of-experiments.htmlhttp://depts.washington.edu/oei/resources/t oolsTemplates/quality_cost.pdf