Understanding Statistical Tools and Techniques

Write-up – 1

Understanding Statistical Tools and Techniques

Implementing an effective quality management system requires measurement, analysis and improvement. ISO 9001:2008 QMS Standard mentions requirements for analysis of data. There are a number of statistical tools and techniques available for monitoring, measuring, analyzing and improving the organization’s processes. We are starting a series of articles under the heading ‘Understanding Statistical Tools and Techniques’. Some of the tools and techniques are as under:

- Problem solving approach ‘DRIVE’
- Brainstorming
- Cause and effect diagram – CED – Fishbone diagram – Ishikawa diagram
- Cause and effect diagram with addition of cards – CEDAC
- Check sheet
- Control chart
- Histogram
- Pareto analysis
- Scatter diagram
- Stratification
- Process mapping
- Process flowcharting
- Force field analysis
- Bar chart
- Matrix analysis
- Tally chart



The use of statistical techniques helps organization in understanding variability. It helps organizations to solve problems. It also helps organization to improve effectiveness and efficiency. The statistical techniques also facilitate better use of available data to assist in decision making. Seven tools from the above are known as basic quality tools. These are:
- Cause and effect diagram – CED – Fishbone diagram – Ishikawa diagram
- Check sheet
- Control chart
- Histogram
- Pareto chart
- Scatter diagram
- Stratification

As per requirements of ISO 9001:2008 QMS Standard, an organization is required to determine, collect and analyze appropriate data. This must include data generated from relevant sources including as a result of monitoring and measurement. The analysis of data must provide information relating to:
- Customer satisfaction (See for reference clause 8.2.1 of the ISO 9001:2008 QMS Standard)
- Conformance to product requirements (See for reference clause 8.2.4 of the ISO 9001:2008 QMS Standard)
- Characteristics and trends of processes and products including opportunities for preventive action (See for reference clause 8.2.3 and 8.2.4 of the ISO 9001:2008 QMS Standard)
- Suppliers (See for reference clause 7.4 of the ISO 9001:2008 QMS Standard)




To improve organization’s processes by means of a systematic approach, people working in the organization require the knowledge of simple kit of tools and techniques. The person who actually works on the processes needs to understand these tools and techniques, so that he can effectively use these tools. Some may think that these tools are complex and require higher knowledge of Mathematics or Statistics. However, we will make the study of these tools and techniques in a language easy to understand. We request our readers to please send/post your comments and suggestions for improvement.