Quality management tools and methodologies used in Six Sigma Six Sigma makes use of a great number of established quality management methods that are also used outside of Six Sigma. The following table shows an overview of the main methods used. 5 Whys Analysis of variance ANOVA Gauge R&R Axiomatic design Business Process Mapping Catapult exercise on variability Cause & effects diagram (also known as fishbone or Ishikawa diagram) Chi-square test of independence and fits Control chart Correlation
Cost-benefit analysis CTQ tree Quantitative marketing research through use of Enterprise Feedback Management (EFM) systems Design of experiments Failure mode and effects analysis General linear model Histograms Homoscedasticity Pareto chart Pick chart Process capability Regression analysis Root cause analysis Run charts SIPOC analysis (Suppliers, Inputs, Process, Outputs, Customers) Stratification Taguchi methods Thought process map TRIZ Business Process Mapping refers to activities involved in defining exactly hat a business entity does, who is responsible, to what standard a process should be completed and how the success of a business process can be determined. Once this is done, there can be no uncertainty as to the requirements of every internal business process. A business process illustration is produced. The first step in gaining control over an organization is to know and understand the basic processes (Deming, 1982; Juran, 1988; Taylor, 1911). ISO 9001 requires a business entity to follow a process approach when managing its business, and to this end creating business process maps will assist.
The entity can then work towards ensuring its processes are effective (the right process is followed the first time), and efficient (continually improved to ensure processes use the least amount of resources). The control chart, also known as the Shewhart chart or process-behaviour chart, in statistical process control is a tool used to determine whether a manufacturing or business process is in a state of statistical control or not. However in the early stages of use the inclusion of these items may confuse inexperienced chart interpreters.
Cost-benefit analysis is a term that refers both to: •a formal discipline used to help appraise, or assess, the case for a project or proposal, which itself is a process known as project appraisal; and •an informal approach to making decisions of any kind. Under both definitions the process involves, whether explicitly or implicitly, weighing the total expected costs against the total expected benefits of one or more actions in order to choose the best or most profitable option. The formal process is often referred to as either CBA (Cost-Benefit Analysis) or BCA (Benefit-Cost Analysis).
Quantitative marketing research is the application of quantitative research techniques to the field of marketing. It has roots in both the positivist view of the world, and the modern marketing viewpoint that marketing is an interactive process in which both the buyer and seller reach a satisfying agreement on the “four Ps” of marketing: Product, Price, Place (location) and Promotion. As a social research method, it typically involves the construction of questionnaires and scales. People who respond (respondents) are asked to complete the survey. Marketers use the information so obtained o understand the needs of individuals in the marketplace, and to create strategies and marketing plans. A failure modes and effects analysis (FMEA) is a procedure for analysis of potential failure modes within a system for classification by severity or determination of the effect of failures on the system. It is widely used in manufacturing industries in various phases of the product life cycle and is now increasingly finding use in the service industry. Failure causes are any errors or defects in process, design, or item, especially those that affect the customer, and can be potential or actual.
Effects analysis refers to studying the consequences of those failures. In statistics, a histogram is a graphical display of tabulated frequencies, shown as bars. It shows what proportion of cases fall into each of several categories. The categories are usually specified as non-overlapping intervals of some variable. The categories (bars) must be adjacent. The intervals (or bands) should ideally be of the same size . Histograms are used to plot density. The total area of a histogram always equals 1. If the length of the intervals on the x-axis are all 1, then a histogram is identical to a relative frequency plot.
The word histogram is derived from the Greek histos ‘anything set upright’ (as the masts of a ship, the bar of a loom, or the vertical bars of a histogram); and gramma ‘drawing, record, writing’. The histogram is one of the seven basic tools of quality control, which also include the Pareto chart, check sheet, control chart, cause-and-effect diagram, flowchart, and scatter diagram. A generalization of the histogram is kernel smoothing techniques. This will construct a very smooth probability density function from the supplied data.
Taguchi methods are statistical methods developed by Genichi Taguchi to improve the quality of manufactured goods, and more recently also applied to biotechnology, marketing and advertising. Taguchi methods are considered controversial among some traditional Western statisticians, but others accept many of his concepts as being useful additions to the body of knowledge. Taguchi’s principal contributions to statistics are: 1. Taguchi loss function; 2. The philosophy of off-line quality control; and 3. Innovations in the design of experiments.