TOTAL QUALITY MANAGEMENT

QUESTION:

BRIEFLY EXPLAIN THE SEVEN TOOLS OF STATISTICAL PROCESS CONTROL.

Statistical process control Statistical process control (SPC) is a method of quality control which

uses statistical methods.

SPC is applied in order to monitor and control a process. Monitoring and controlling the process ensures that it operates at its full potential.

At its full potential, the process can make as much conforming product as possible with a minimum (if not an elimination) of waste (rework or trash).

SPC can be applied to any process where the "conforming product" (product meeting specifications) output can be measured.

Key tools used in SPC include control charts; a focus on continuous improvement; and the design of experiments

The Seven Tools of Quality

1. Control chart

2. X-Bar and R Charts3. Pareto chart

4. Flow chart

5. Cause and effect diagram

6. Histogram

7. Scatter diagram

The Pareto graphically summarizes and displays the relative importance of the differences between groups of data. A Pareto chart can be constructed by segmenting the range of the data into groups.

A flowchart is important project development and documentation tool.It visually records the steps, decisions, and actions of any manufacturing or service operation and defines the system, its key points, activities and role performances.

A histogram is used to graphically summarize and display the distribution of a process dataset. It can be constructed by segmenting the range of the data into equal-sized bins (segments, groups, or classes). The vertical axis of the histogram is the frequency (the number of counts for each bin), and the horizontal axis is labeled with the range of the response variable.

Cause and Effect Diagram A problem is systematically tracked back to

possible causes. The diagram organizes the search for the root cause of a problemA similar diagram can be used to systematically search for solutions to a problem.

Scatter charts It is similar to a line graph except that the data point are

plotted without a connecting line drawn between them. Scatter charts are suitable for showing how data points compare to each other. At least 2 measured objects are needed for the query (one for x-axis and one for y-axis)

Control Charts A broken line graph illustrates how a process behaves

over time. Samples are periodically taken, checked, or measured, and the results are plotted on the chart. The charts can show how the specific measurement changes, how the variation in measurement changes, or how the proportion of defective pieces changes over time

X-Bar and R Charts

The most commonly used of the control charts and the most valuable.They are ideal tools to improve product quality and process control and help to drastically reduce scrap and rework while assuring the production of only Satisfactory products.They can be used for controlling every step of production process, for the acceptance/ rejection of lots, and for early detection of equipment or process failure