1. Performance: How well the product functions
2. Conformance: How well the product conforms to the specifications or standards set for it.
3. Features: How many secondary characteristics does the product have to enhance its basic function
4. Aesthetics: How attractive the product is.
5. Reliability: How well does the product maintain its performance during a certain given time period.
6. Durability: How long the product lasts in use.
7. Serviceability: How easy is the product to maintain.
8. Safety: How little, if any, is the risk to the users and those in the vicinity of the users
(a) when the product is in use, and
(b) when the product is thrown away after its useful life.
9. User friendliness:
(a) How easy is it to use. How easy is it to operate with
(b) Is it ergonomically all right
10. Customising ability: How easily can the product be modified
(a) in case the requirements of the customer were to change ,or
(b) in order to accommodate improved / additional features in the future to suit the customer’s needs then
11. Environment Friendliness: How safe is the product for the environment
(a) while it is being used and
(b) when it is discarded after its use
While quality has become an essential prerequisite these days, it still has a great potential to be used further as a strategic measure. This is apart from the considerations of the cost of quality. A good product design contributes, in a large measure, to the product’s quality. The various attributes of product quality, as derived from a good product design, are mentioned above.
In purely cost terms, the cost of quality generally constitutes a significant portion of the life cycle costs of a product. Therefore, designing good quality into the product would substantially reduce the costs over the product’s life cycle. Taguchi has been one of the pioneers of this philosophy of quality. The concept of a ‘robust design’ of a product where the product is designed to be robust enough to perform under several external variations flows from this thinking.
In the context of ‘designing quality in’, it may be worth while to look into some of the quality characteristics such as reliability and user friendliness. The initial manufacturing costs may increase as the reliability is improved, but the overall life cycle costs can decrease. The cardinal principle guiding improved reliability and also user friendliness is to keep the design simple. Simple designs tend to minimize human errors in using/handling the product. The designer has to anticipate the possible human errors. Data on field failures of existing similar products of the company may offer some tips in this respect. Another method to improve reliability is to have redundancy (i.e. if one part/system fails, an alternate part/system would take over the function). This may increase the initial costs to the company but the overall costs in the long run may reduce. Similar thinking operates in cases where the designers design the product for use conditions that are harsher than those generally encountered. Another important tip is to improve the weakest component or part of the product and give priority to it. Thus, the weakest links are strengthened first. Indeed, these are very simple and seemingly obvious tips. But, they would go a long way in improving reliability of the product. The principles of user friendly design are mentioned above.
In addition to Robust Design and Design of Experiments (DoE), the other tools to include quality into a product’s design are Quality Function Deployment (QFD) and value Engineering (VE), QFD and VE very emphatically being the customer’s point of view into the design of a product.