Module I.Lecture 2 Introduction to Quality Management.

Module I. Introduction to Quality Management

Lecture 2 - What do we mean by Product and Service Quality?

‘Quality’ can be defined as a standard measure of how well a product or service conforms to the specified standards, so as to meet the customer requirements. Quality has been defined by various quality gurus. Juran defined quality as ‘fitness for use’ in 1974. Crosby, in 1979, defined the quality as ‘conformance to requirements or specifications.’ Garvin, in 1984 divides the definition of quality into five major categories—namely, transcendent, product-based, user- based, manufacturing-based and value-based. In addition, he also identifies eight attributes that may be used to define product quality: performance, features, reliability, conformance, durability, serviceability, aesthetics, and perceived quality. The definition proposed by Crosby seems more appropriate from both service and manufacturing perspective. However, terms such as delighting customers, robustness, reducing variability can also be associated when organization talk about quality. The driving force to determine the level of quality that should be designed into a product of service is ‘The customer’. Quality also has a time dimension. In other words, as the need and preference of customer changes with time, the level of quality or degree of customer satisfaction also changes. Thus, quality, in this sense, is not constant.It is a crucial parameter that differentiates an organisation from its competitors.Thus, term quality also implies different levels of expectations from different segment of consumers.

Now, who are the customers?

There are two distinct types of customers- external and internal. An external customer may be the one who uses the end product or service, the one who purchases the end product or service, or the one who influences the sale of the end product or service. An external customer exists outside the organization.

An internal customer is also important. Every function within an organization, whether it is engineering, order processing, or production has an internal customer. That means each function receives a product or service from another function and, in exchange, provides a product or service to a subsequent function. From process perspective, every process is considered a

customer of the preceding process. Grinding process can be internal customer to boring process.

A diagrammatic representation is provided below (Figure1-1) to show internal and external customer in the supply network perspective.

Figure 1-1: Customer from basic Supply network Perspective

From the customers' perspective, service is the combination of the customers experience and their perception of the outcome of the service. The term service quality (Johnston and Clark, 2008) is often used to mean different aspect. Some may use the term to mean how the customer is treated overall. This may be more accurately called ‘quality of service’, as opposed to service quality, which can mean the entirety of outcome and experience. Sometimes service quality is used to mean the same as satisfaction, i.e. perceived service quality.

Few definitions, which are important while we discuss on product quality is worth mentioning:

Quality Characteristics

There can be more than one element that defines the intended quality level of a product or service. These elements are so-called ‘quality characteristics’. Quality characteristics may be of several types (Montgomery and Runger, 2010). It may be Thus, the gross weight of a coke cans, the tensile strength of a bar, the specific gravity of a liquid, and so on. There may be some intangible characteristics, such as the taste, smell beauty. There can also be ethical characteristics such as honesty, courtesy, friendliness which are difficult to measure and define.

Variables and Attributes

Quality characteristics can fall into two broad classes, viz. variables and attributes. Characteristics that are measurable and are expressed on a numerical scale (ordinal or interval) are called variables. The diameter of a bore expressed in millimeters is a variable, or density of a liquid in grams per cubic centimeter or customer satisfaction expressed in a scale of 7. If we express characteristics only in terms of conforming and defective, it falls in the attribute or nominal category.

Defects and Def ective Unit

Before defining an attribute, the terms defect and a defective unit should be defined. Defect is a quality characteristic that do not meet its stipulated specifications. Let's say the specifications of the thickness of steel washers are 3 ± 0.1 millimeters (mm). If we have a washer with a thickness of 3.15 min, then its thickness is a defect.

The American National Standards Institute (ANSI) and the American Society for Quality Control (ASQC) provides a definition of a defect as stated in ANSI/ASQC Standard:

‘A defect is a departure of a quality characteristic from its intended level or state that occurs with a severity sufficient to cause an associated product or service not to satisfy intended normal or reasonably foreseeable usage requirements.’

A defective unit has one or more defects such that the unit is unable to meet the intended standard or use and is unable to function as required. An example of a defective unit might be a cast iron cylinder that has an internal diameter and a weight that both fail to satisfy specifications, thereby making the unit dysfunctional.

A quality characteristic is said to be an attribute if it is classified as either conforming or defective to a stipulated specification. A quality characteristic that is not measured on a numerical scale is expressed as an attribute. For example, the smell of a perfume is characterized as either acceptable or not; the color of a cloth is either acceptable or not. Variables are treated as attributes because of their simplicity to measure them this way or because it is difficult to obtain data on them. Many examples may be cited in this category. For instance, the diameter of a engine cylinder is, in theory, a variable. However, if we measure the diameter using a go/no-go gauge and classify it as either conforming or defective (with respect to some established specifications), then the characteristic is expressed as an attribute. The reasons for using a go/no-go gauge, as opposed to a micrometer, could be economical. A measurement by go/no- go gauge may be much shorter and consequently less expensive.

Standard or Specification

As the definition of quality involves meeting the requirements of the customer, these requirements need to be documented. A standard, or a specification, refers to a precise statement that validates the requirements of the customer; it may relate to a product, a process, or a service. For example, the specifications for a bore might be 3 ± 0.1 centimeters (cm) for the inside diameter, 5 ± 0.2 cm for the outside diameter, and 12 ± 0.5 cm for the length. This means that for the bore to be acceptable to the customer, all the three dimensions must be within the specified limit.