Designing A Quality Product

DESIGNING QUALITY FOR PRODUCTS

DESIGNING QUALITY FOR PRODUCTS

DESIGNING QUALITY FOR PRODUCTS

The design of a production system is a challenging activity. Requirements from the market for agile production systems and requirements from employees for more autonomy and responsibility demand a new way of designing production systems. The human element possesses qualifications and creativity that should be used more effectively in the design procedure.

Product development translates customer expectations for functional requirements into specific engineering and quality characteristics. For traditional products, this process is not complicated and can be achieved by experienced design engineers without using any special techniques. For modern products, it is useful to document and analyze the design logic. This means starting with the desired product attributes and then identifying the necessary characteristics for raw materials, parts, assemblies, and process steps. Such an approach goes under a variety of names, such as systems engineering, functional analysis systems technique, structured product/process analysis, and quality function deployment.

DESIGINING FOR ROBUSTNESS

Robust design method was pioneered by Dr. Genichi Taguchi after the end of the Second World War. This method has evolved over the last five decades. Companies around the world have saved millions of dollars by using the method in diverse industries such as automobiles, xerography, telecommunications, electronics, software, etc. The Robust design method can also be called the Taguchi Method.

Taguchi's quote: Robust Design: Not just strong. Flexible! Idiot proof! Simple! Efficient! A product/process that produces consistent, high-level performance "despite being subjected to a wide range of changing client and manufacturing conditions...."

Traditional engineering focuses on solving problems, failure analysis, use of a repetitive process of design-build-test, testing one factor at a time, firefighting, and studying in detail the problems associated with interactions of the factors involved. This approach costs more, takes more time, and isn't always successful.

Taguchi's approach allows experiments to be performed and prototypes to be tested on multiple factors at once so that the product/process becomes insensitive to use-conditions and other uncontrollable factors. This is called Robust Design, and it provides a more efficient, cost-effective way to improve products and processes.

This revolutionary approach to engineering and design represents one of the most significant breakthroughs in product and process design since the Quality Revolution began.

It provides a method for designing products and processes that are minimally impacted by external forces, such as environment, client use, or manufacturing conditions.

This is accomplished using Energy Transformation principles for improving the desired output targeted toward perfect performance, rather than attempting to suppress symptoms.

It enables engineers to:

* Develop products and processes which perform consistently as intended under a wide range of user's conditions throughout their life cycle (durable and reliable)

* Maximize robustness-improve the intended function of the product by developing and increasing insensitivity to noise factors which tend to degrade performance

* Develop or change product formulas and process settings to achieve desired performance at the lowest cost and in the shortest time

* Simplify designs and processes to reduce cost

The Robust Design approach is based on an Energy Transformation model for engineering systems (mechanical, electrical, chemical, etc.). This unique approach to achieving Quality Assurance and Robustness during the design phase utilizes identification of the Ideal Function of a product or process, as opposed to traditional methods which focus on "symptom analysis" as a basis for improvement.

The Robust Design system simultaneously yields:

* Significantly improved quality, reliability, and durability

* Reduced manufacturing costs

* Reduced design cycle times

* New, proprietary knowledge

DESIGNING FOR PRODUCTION

Decisions made during design are the dominant influence on product costs, ability to meet specifications, and the time required to bring a new product to the marketplace. Once these decisions are made, the cost of changes in the design can be huge. An important set of decisions is the selection of specifications for product characteristics to be controlled during production. Specification limits specify the allowable limits of variability above and below the nominal value set by the designer.

The selection of limits has a dual effect on the economics of quality. The limits affect:

* Fitness for use and hence salability of the product.

* Costs of production and quality.

A technique called design for manufacturability focuses on simplifying a design to make it more producible.

The emphasis is on

* Reducing the total number of parts

* Reducing total number of different parts

* Reducing the total number production operations

* Reducing source of errors and improve quality

* Easy and quick assembly

* Reducing waste and economic production

Value engineering tools have been useful in achieving design simplification. Use of software enables the designers to learn the principles for ease of manufacturing analogous to reliability, maintainability, and safety analysis. Planning for inspection, packaging, transportation, and storage also has an impact on the product design.