Quality Management Tools And Techniques

The tools and techniques most commonly used in Quality management and process improvement are:

  • Cause and effect diagram
  • Control Charts
  • Histogram
  • Pareto Charts
  • Flow chart
Cause and effect diagram

fishboneCause and effect diagram is very helpful to find the root cause of the defect. Cause-and-effect diagrams show the relationship between the results of problems and the root cause of these problems. This diagram shows all the primary and secondary causes of a problem and the effect of all the proposed solutions. This Ishikawa diagram is also called fishbone diagram due to its fish-like shape. In the above diagram: poor training, old equipment, funds are the causes and “Excessive downtime” is the effect.

Control Charts

controlControl charts measure the results of processes over time and display the results in the form of a graph. By using control charts one can determine whether process variances are in control or out of control. A control chart is works on sample variance measurements, from the samples chosen and measured, the mean and standard deviation are determined.

Let’s assume from a sample you have determined the measurement that mean is 300 and the standard deviation equals 44.72. Three standard deviations on either side of the mean become your upper and lower control points on this chart. In this case 3 standard deviations is equal to 300 +- (134.16). Therefore, if all control points fall within plus or minus three standard deviations on either side of the mean, the process is in control. If points fall outside the acceptable limits, the process is not in control and corrective action is needed. UCL and LCL are Upper control limit and lower control limit respectively. USL and LSL are upper specification limit and lower specification limit.

Histogram

histogramHistograms are a type of bar charts that depict the distribution of variables over time. This represents the distribution by mean. This graph may take different shapes based on the condition of the distribution. Histogram can be used to measure something against time i.e. the graph is plotted with a variable on x-axis and time on the y-axis.

Consider the following example: The following histogram shows number of hits on the company’s website in different time of the day. The x-axis shows the number of users or customers active on the website and the y-axis shows the time of the day.

 

Pareto chart

paretoPareto observed that 80 percent of issues occur due to 20% reasons. Over the years, others have shown that the 80/20 rule applies across many disciplines and areas. So it was a good idea to identify and focus on that category of defects which covers the maximum portion. It is a special form of vertical bar chart and used to identify the first few major sources responsible for the problem. In the figure below the total no. of defects are plotted against the reasons for those defects. The problems are rank-ordered according to their frequency and percentage of defects. By doing this ordering it is easier for you to identify the primary areas for corrective action.

 Flowchart

Flowcharts are logical steps in a logical order so as to accomplish an objective. Flow charts are drawn with the use of geometrical objects like rectangular, rhombus, parallelogram, activities, decision points to  in a process. Flowcharting can help identify where quality problems might occur on the project and how problems happen. There are different software tools in the market today for drawing flow charts, such as MS Visio.

The quality policy is a guideline created by the top management that describes what quality policies should be adopted by the project team, in line with other companies. These tools and techniques are very helpful for a project manager to understand it and incorporate it and deliver a quality product.

About Aditi Malhotra

Aditi Malhotra is the Content Marketing Manager at Whizlabs. Having a Master in Journalism and Mass Communication, she helps businesses stop playing around with Content Marketing and start seeing tangible ROI. A writer by day and a reader by night, she is a fine blend of both reality and fantasy. Apart from her professional commitments, she is also endearing to publish a book authored by her very soon.

2 thoughts on “Quality Management Tools And Techniques”

  1. Collin Wright

    Your blogs quality management tools and techniques is very informative and I gain my knowledge more.

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