Basic Quality Tools

Quality Management has become a full-fledged science today. It has emerged from being subjective and more perception based to more objective and measurable. Processes and standards are the backbone of modern quality management. Quality Management today uses various data driven statistical tools for meaningful assurance and control of quality. Sessions on statistical tools and other quality tools are an essential part of a Professional Project Management course.

Focus is on Process Compliance and Continuous Process Improvement for quality management. This is where there a generic set of basic quality management tools are used. Below is a list of some of the basic quality management tools. As per CQE (Certified Quality Engineer) Handbook 95% of quality related problems can be solved with these tools.

• Cause and effect diagram
• Control Charts
• Flowcharting
• Histogram
• Pareto Chart
• Run Chart
• Scatter diagram

1. Cause and Effect Diagram 

Root cause Analysis (RCA) is an integral part of Quality Management. This is done to prevent similar defects from happening in future. Cause and Effect diagram is used to do root cause analysis. This is also known as Fish-bone Diagram and Ishikawa Diagram. This tool helps stimulate good brainstorming within the team doing root cause analysis and helps organize their thoughts. The team asks “why” multiple times for a given problem and tries to find the root causes. Below is a sample fishbone diagram.

2. Flowcharting 

 Flowchart is an integral part of quality management tools.  Flowchart in the context of seven basic quality tools is defined as to describe the graphical presentation of a process. 

A process can be viewed as a sequence of activities performed collectively to achieve specific objectives. These sequences of activities include set of inputs, decision branch nodes and resultant output. A flowchart can be used to visualize the sequence of events of a process either performed sequentially or in parallel.

During Quality Planning, flowcharting can help the project team to anticipate quality problems that might occur during a process. An awareness of potential problem can result in development of test procedures or approaches for dealing with them.

Below is a sample Flowchart:

3. Control Charts 

Control Chart graphically helps you to determine if the process performance is within acceptable limit. A control chart can be used to monitor project performance figures such as cost or schedule variance and also many other performance metrics.

Control charts can be used to 

1. Check the stability of the process
2. Monitor the conditions which may require the team to react
3. Monitor consecutive run of results in any pattern 

A Control Chart will have the following components of a process:

• Upper Control Limit
• Lower Control Limit
• Mean/Average

4. Histograms 

Histograms are bar charts. Histograms are used to show the frequency or number of occurrences of a particular event. Histograms are also used to show the number of defects being contributed by different root causes.

A sample histogram is shown below.

5. Pareto Chart

Pareto chart is an ordered histogram. The histograms are plotted in a descending order of frequency showing each root cause and corresponding number of defects contributed by them. The Pareto chart is based on the famous 80-20 rule.

It helps to focus on the significant root causes and focus on eliminating them.

Pareto charts: 

1. Helps focus attention to the most critical issues.
2.  Prioritizes potential cause of the problem.
3.  Helps identify the critical few from the uncritical many.

6. Scatter Diagram

Scatter diagram is a statistical tool which is used to show Co-relation between 2 different variables. The scatter diagram graphs pairs of numerical data, with one variable on each axis, to look for a relationship between them. If the variables are correlated, the points will fall along a line or curve. The better the correlation, the closer the points will be around the line.

For example, an organization may like to check if there is a co-relation between the hours of training given to employees and the number of defects being created by them.

7. Run Chart 

A Run Chart is a line graph showing data points over time. By collecting and charting data over time, you can find trends or patterns in the process. The data may show:

• Variances
• Trends (performance improving, deteriorating, or remaining constant)

Many organizations apply run charts to track whether their key performance indicators (KPIs) behave in expected lines.