Quality by DesignChandran Udumbasseri, Technical consultant

IntroductionQuality is a concept that has been used by people in every walk of life - daily life, business, industry, etc. The day in our life begins with the strict adherence to quality in all activities, from cleaning our body, food, clothing, the way we look, aesthetics, etc. Thus quality is not a new concept. It was there from time immemorial. But the degree to which each person adheres to quality differs. Usually the degree of quality is measured by comparing to a bench mark value or grade. In the morning while starting to brush our teeth, we use tooth paste. Once we squeeze the paste from the tube sometimes more paste may come out and fall after covering the surface of brush. Then it is natural that we react to it. We conclude that the quality of the tooth paste is not good, because it is not meeting your requirement. In this case your requirements are,

Once you squeeze the tube the paste coming out of the tube should be controllable by your squeezing pressure.

It should not be in the slurry form. It should be semi solid in nature. The paste that has come out should just cover the brush surface to the level

that you wanted.This explains the need of the customer and how the need is translated to requirements. The above instance does not compare to a previous result from a similar product, but the need of the end-user, the quality concept that he formulated for his own practical purposes.When you decide to purchase a car, you think of its cost, its performance based on petrol consumption, facilities in the car, etc. if your budget is for Rolls Royce your choice will be for more facilities rather than petrol consumption. Then your concept for quality of the vehicle is based on elegance of the car, facilities in the car, aesthetic taste, etc. If your budget allows you only to purchase Toyota model, then mostly you will be concerned about the performance of the car based on petrol consumption. In both cases the quality specification for the car changes. The fitness for use of the car is based on price tag, mileage per liter of fuel, minimum facilities in the car, etc. Here the quality concept is formulated by comparison.

Quality is associated with excellence. Sometimes it is difficult to achieve it. The degree of excellence is based on the specification or criteria that we formulate so that the final outcome is classified as excellent, good or poor performance.Customer is the main person who decides the quality of the product or service of a producer or supplier. There are multiple elements that are used to evaluate the fitness of a product or service for its use. These elements constitute the characteristics of quality and are the building blocks for designing quality into the product.A product specification explains limits of these quality characteristics agreed between the customer and the manufacturer or supplier of the product. Gold ornaments having purity 916 Hallmark shows the publically accepted purity of gold used for making ornament. Also it tells the customer what percent of copper is present in the ornament. This Hallmark is the criteria that a customer looks while purchasing the gold ornament.A doctor prescribes a drug to a patient by considering specification of the drug and its performance as described in the company’s brochure and by the medical representative. He adds this information to his knowledge of the drug and prescribes the drug to the patient. Doctor depends on description given by the company and their representative. The quality of the drug is ascertained after evaluating its performance for curing the disease of the patient. The label on the drug explains the content or specification. But this does not reveal the ability of the drug to cure the disease of the patient at faster recovery rate or whatever it may be criterion. Here the quality is decided by the performance and not by specification.Products with Trade names of well established companies are generally accepted by the customer as having required quality that the customer is looking for. Here the manufacturer’s reputation for offering high quality products is the bench mark. Sometimes such reputation works well for all the consumable products marketed by that company.While purchasing textile goods, the customer just go for the company reputation and also price. The concept that “higher the price better the product quality”, is an unwritten quality rule that customer usually follow.It is not always true that the product offered by a company with specified product specification need to perform as per the specification even though the product passed company’s quality control test. The customer looks for product guarantee period, warranty period and after sales service. The manufacturer and customer are septic about the long term usability and performance of the product. This

additional offer from product supplier is an added advantage to ensure that quality of the product is properly maintained by the supplier even though additional service charge is deduced by the supplier from the customer.Parts of some products that usually undergo wear and tear, like automobiles, engines, pumps, etc need to be replaced to maintain the quality of the product. The quality of each part is checked and ensured separately and total performance of the product verified.

Elements of qualityQuality is an excellence concept which can be quantified sometimes by measuring parameter but not always. It would be better if the attributes are quantified. Some traits cannot be quantified. The characteristics of quality may be classified as given below:

1. Appearance , visual-specific and totalAppearance of a product can be judged visually. The quality of painting on a car is verified by specifically looking visually in detail at all parts of the car.The quality of a painting on a canvas or board is visually judged and not by scrutinizing the painting in detail. The quality of the painting is judged by looking at its totality and not at separate parts.

2. Aesthetics: taste, beauty, etc.All eatables are judged by taste. Food item without taste and flavor is not acceptable. These are approved for its quality by the customer by tastingThe concept ‘Beauty’ is unique to itself. It’s acceptance for quality is also individualized because the beauty a person see at a thing, living or non-living, is his own approval and not general. The quality acceptance criteria vary from person to person for ’beauty’.

3. Ethical: courtesy, honesty, etc.The receptionist sitting just in front of a company office gives an impression how the company management works. The customer approaches the receptionist and communicates to know about the organization and related information for which he is there. The courtesy of the receptionist impresses the customer and he feels it as a good quality of the company.The honesty of an organization always creates positive opinion about it. Customer pays credit to such organization.

4. Time based: Reliability: product reliability for long term usage without major maintenance problem is a customer requirement. A product that is

used properly without any accidental breakdown from the customer’s carelessness can be considered as good quality product.Maintainability: if properly maintained as directed by the supplier of the product, the durability of the product can be increased by undertaking preventive maintenance, that is scheduled maintenance work with changing consumables at specified time by the producer. This also gives customer satisfaction on the performance of the product.

5. Warranty: warranty period is after sales period up to which the producer takes the responsibility of the product for its non-functioning provided that the customer operated the product as instructed in the user’s guide. In such case the product may even be replaced by the producer. This type of warranty also satisfies the customer.

6. Product property: the physical and chemical property. Product specification usually gives the maximum and minimum tolerable limits of certain measurable properties of the product. Purity, chemical performance, physical characteristics, specified chemical reactions, etc are measurable properties that can be used for monitoring the quality.

7. Physical and structural characteristics: dimensional measurement: dimension like length, width, height, weight, volume, rotations per time, strokes, speed, viscosity, surface tension, diameter, frequency of vibration, intensity of light transmission and absorption, refraction, flow rate, etc are measurable. Product specification can be formulated based on dimensions like length, width, height, diameter for materials, space, surface, etc. Space like land, physical structure, solid materials, etc can have specification with dimensional measurements.Liquids can be specified by weight, volume specific gravity, refractive index, viscosity, surface tension, solubility, flash point, clod point, boiling point, freeing point, etc.Solid materials can be specified by the same parameters which are measurable quantities. Other measurable quantities are tensile, impact, compression and bursting strength, etc.Vehicle specification contains dimension and weight, performance parameters like speed limits, fuel consumption per kilometer running, total load limits, etc.

8. Non measurable characteristic: cracks, dents, breakages, etc are non-measurable.

Number of cracks can be reported, but their complete information like, depth of crack, length, nature of crack etc remains un-measurable. A crack on a plastic molded item may be due to processing problem, impact with other objects, environmental etc. The causes for all these are many. Crack on a metallic product may be due to corrosion and there are many types of such corrosion cracking

9. Defect counting: mass produced items like plastic bottles are inspected for separating defective items from good items. The defect may be surface defect, assembly defect, packing defect, broken items etc.

Quality definitionsA wide range of definitions are formulated in the course of the time through which the present quality concept has reached. As the costumers needs and requirements changed so the concept of quality changed from that of product acceptance-rejection to the present state of quality having precise characteristics and elements with different techniques to evaluate them. Some of the definitions are given below:

1. “Quality consists of the capacity to satisfy wants”, C.D Edwards (Meaning of Quality, Quality Progress, 1968).

2. “Quality is the degree to which a specific product conforms to a design or specification”, H.L Gilmore (Product conformance cost, Quality Progress, 1974)

3. “Quality means conformance to requirements”, P.B.Crosby (Quality is Free, 1979)

4. “Quality refers to the amount of unpriced attributes contained in each unit fo the priced attribute”, K.B.Leifler (ambiguous changes in Product Quality, American economic review, 1982)

5. “Quality is the degree of excellence at an acceptable price and the control of variability at an acceptable cost”, R.A.Broh (Managing Quality for Higher Profits, 1982)

6. “Quality is fitness for use”, Joseph Juran & Frank Gryna (Juran’s Quality Control Handbook, 1988)