Quality Management

HYPOTHESIS TESTING Population parameters (say mean, variance) of any characteristic which are of relevance in most of the statistical studies are rarely known with certainty and thus estimated based on sample information. Estimation of the parameter can be a point estimate or an interval estimate (with confidence interval). However, many problems in engineering science and management require that we decide whether to accept or reject a statement about some parameter(s) of interest. The statement which is challenged is known as a null hypothesis, and the way of decision-making procedure is so-called hypothesis testing. This is one of the most useful techniques for statistical inference. Many types of decision-making problems in the engineering science can be formulated as hypothesis-testing problems. If an engineer is interested in comparing mean of a population to a specified value. These simple comparative experiments are frequently encountered in practice and provide a good foundati...

Module – 2 Process Quality Improvement What are the graphical and statistical techniques commonly used for understanding current state of quality? What are the process quality monitoring, control and improvement techniques? Systematic solution approach to any quality improvement activity is critical and always emphasized by quality gurus (Juran, Deming, and Shewart). Various tools and techniques are commonly used to identify the critical control variables. The very basic techniques used in quality management is 7 QC Tools, which consist of Pareto Diagram, Process Flow Diagram, Cause and Effect Diagram, Check Sheets, Histogram, Run Charts, and Scatter diagram. Additional statistical tools used are hypothesis testing, regression analysis, ANOVA (Analysis of Variance), and Design of Experiment (DOE). In the following section, we will go through each and every technique in a greater detail. 7 Q C TOOLS P a reto Diagram Alfredo Pareto (1848-1923) conducted extensive studies of distribu...

Module II. Process Quality Improvement L ec t ure -1 Why process quality improvement is important? From operations management perspective, a process is any activity or group of activities that takes one or more inputs, transforms them, and provides one or more outputs for its customers (internal or external). The key to success in an organization is to understand how their processes work to deliver the required outputs. Any process should add value and unnecessary waste activities should be eliminated from the process steps, as per definition in Lean Management philosophy. In the context of Quality Management philosophy, process is transformation of inputs into output, which satisfies the required Quality Characteristics defined by the customers. These characteristics are called ‘CTQ’s’ (Critical-to-Quality) or ‘responses’. The transformation happens by controlling few vitals critical input and process variables (x1 ...xp) known as controllable variables. These variables actually inf...

Module I. Introduction to Quality Management L ec t ure 5 -What do we mean by Quality Cost? Quality costs are defined as those costs that are associated with the non-achievement of product or service quality as defined by the requirements established by the organization and its contracts (agreements) with customers. In simple terms, quality cost is the cost incurred by the firm because of producing poor quality products. Measurement and analysis of various cost aids in tracking the impact of an effective quality management system. Quality costs can be summed up as costs of preventing of non-conformance of requirements, inspecting product/service for non- conformances and failure in meeting specifications. The American Society for Quality Control (1971) has defined four major categories for quality costs , which are provided below: Prevention Costs Prevention costs are incurred in planning, implementing, and maintaining of a quality practice. It include salaries and developmental c...

Module I. Introduction to Quality Management L ec t ure 4 - What are the underlying quality philosophies suggested by Deming, Juran and Crosby? Several quality guru’s, such as W. Edwards Deming. Philip B. Crosby, and Joseph M. Juran, has made significant contributions in the field of quality. They are largely responsible for the global adoption and integration of quality management in industry. They preached that management commitment is the key to a successful program in quality. They also emphasized that any philosophy to improve quality in a company needs time and cannot occur overnight. W. Edwards Deming is credited with the impressive turnaround in Japanese industry after World War  X. Deming's philosophy emphasizes the role of ‘management of the problems’ that industry faces. Deming said that about 85% of the problem can be solved only by management. These involve changing the method of operation and are not by scolding the workers. His idea was to improve process and not ...

Module I. Introduction to Quality Management L ec t ure 3 - What are the dimensions of quality? Before we discuss on dimensions of quality, we must discuss three aspects associated with definition of quality: quality of design, quality of conformance, and quality of performance. Quality of Design Quality of design is all about set conditions that the product or service must minimally have to satisfy the requirements of the customer. Thus, the product or service must be designed in such a way so as to meet at least minimally the needs of the consumer. However, the design must be simple and also less expensive so as to meet the customers' product or service expectations. Quality of design is influenced by many factors, such as product type, cost, profit policy, demand of the product, avail- ability of parts and materials, and product reliability. Quality of Conformance Quality of conformance is basically meeting the standards defined in the design phase after the product is ma...

Module I. Introduction to Quality Management L ec t ure 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 ‘ f itness for use ’ in 1974. Crosby, in 1979, defined the quality as ‘ c onformance 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, re...

Introduction to Quality Management L ec t ure – 1 How the concept of Quality Management evolved over time? From ancient time, quality of goods and services are monitored directly or indirectly. If we look at construction of the pyramid, Greek ancient arts, crafts, and architectures, Roman-built cities, it clearly demonstrates artists and engineers commitment for achieving the excellence in quality. However, till 1800, production of goods and services was primarily done by small group of individuals. These small groups were often family businesses. Thus, the standard of quality was controlled and set by individual who was in turn also responsible for producing the item. This phase, comprising the time period up to 1900, is called the period of ‘Operator Quality Control’. The entire product was manufactured by a single person (or operator) or by small group of persons, who essentially controlled quality. Thus, controlling and improving quality of the product was aligned with the phil...