Thursday, September 14, 2017

PMP Protein: Seven Basic Tools of Quality

By Sathish Babu, PMP

Every organization uses various tools and techniques for quality management on a project. As a project manager, you should know, identify and pick the correct tools and techniques to manage and control the quality of your project. 

One of the important set of tools used in organization is “7 basic quality tools”. These tools can provide much information about problems in the project and hence assist to derive solutions for the same. Let’s take a closer look at each one of them to see what makes them unique.

1. Cause and Effect Diagram
Description: Also, known as Ishikawa or fishbone diagrams. It is a graphical tool that helps identify, sort and display possible causes of a problem or quality characteristics. It is frequently used to find the root causes of the defects.

  • Helps determine root causes.
  • Encourages group participation.
  • Uses an orderly, easy-to-read format.
  • Indicates possible causes of variation.
  • Increases process knowledge.
  • Identifies areas for collecting data.



2. Flow Chart
Definition: It is a diagram that uses graphic symbols to depict the nature and flow of the steps in a process. It can be used to better understand a process in order to determine which steps add value to the process and which ones don’t (and which therefore can be eliminated).

  • Promote process understanding.
  • Provide tool for training.
  • Identify problem areas and improvement opportunities.
  • Helps for decision-making processes.



3. Check Sheet
Definition: Also, known as Tally Sheet or Checklist is a used for gathering and organizing data. It also helps to keep track of data such as quality problems uncovered during inspections.

  • Records data for further analysis.
  • Provide historical record.
  • Introduce Data Collection methods (where, what, who and how).


4. Histogram
Definition: It is a bar chart that shows the distribution of data and a snapshot of data taken from a process. If the histogram is normal, the graph takes the shape of a bell curve. If it is not normal, it may take different shapes based on the condition of the distribution.

  • Summarize large data sets graphically.
  • Compare measurements to specifications.
  • Communicate information to the team.
  • Assist in decision making.

If a project had 125 defects, you might think that they all were critical. So, looking at the chart like the one below would help you to get some perspective on the data.

5. Pareto Chart
Definition: It is a bar chart arranged in descending order of height from left to right. Bars on left relatively more important than those on the right. Joseph Juran adapted Vilfredo Pareto’s 80/20  rule to create the 80/20 principle which states that 80% of the defects are usually caused by 20% of the root causes. 

  • Breaks big problem into smaller pieces.
  • Identifies most significant factors.
  • Shows where to focus efforts.
  • Allows better use of limited resources.
  • Help focus attention on the most critical issues.
  • Prioritize potential “causes” of the problems.
  • Separate the critical few from the uncritical many.


6. Control Chart
Definition: It is used determine if the results of a process are within acceptable limits or not. These limits, i.e., upper control limit (UCL) and lower control limit (LCL), are decided by project manager and other stakeholders. If the variables are within the limit, the project will be treated ‘in control’. There is a line in the middle of the control chart which is known as ‘mean’. It represents the middle of the range of an acceptable variation. If seven variables are found in one side of the mean, but within the control limits, it is known as rule of seven and the project will be treated as ‘out of control’. There is also upper and lower specification limit (USL and LSL) which are decided by the end customers.

These charts allow you to identify the following conditions related to the process that has been monitored,
  • Stability of the process.
  • Predictability of the process.
  • Identification of common cause of variation.
  • Special conditions where the monitoring party needs to react.

Example (reference source - “I Want To Be A PMP” book):

7. Scatter Diagram
Definition: It is used to study and identify the possible relationship between the changes observed in two different sets of variables. A regression line (or trend line) is calculated to show the correlation of variables, and can then be used for estimation and forecasting. 

Given below are the steps to construct a Scatter diagram.
  • Collect two pieces of data and create a summary table of the data.
  • Draw a diagram labeling the horizontal and vertical axes.
  • It is common that the “cause” variable be labeled on the X axis and the “effect” variable be labeled on the Y axis.
  • Plot the data pairs on the diagram.
  • Interpret the scatter diagram for direction and strength.


1.Which of the following tools and techniques is used to show which categories of defects are most common?
A. Control charts
B. Pareto charts
C. Checksheets
D. Flowcharts 

2. Which tool and technique is used to analyze trends?
A. Scatter chart
B. Run chart
C. Checklist
D. Flowchart

3. Which Control Quality tool is used to analyze processes by visualizing them graphically?
A. Checklists
B. Flowcharts
C. Pareto charts
D. Histograms

4. Which of the following is associated with the 80/20 rule?
A. Scatter charts
B. Histogram
C. Control chart
D. Pareto chart

1.B, 2.B, 3.B, 4.D

1. “ Seven Basic Quality Tools” from PMBOK Guide 5th Edition.
2. “8.3: The 7 Basic Tools of Quality” from Book - I Want To Be A PMP by Satya Narayan Dash.
3. “Chapter - 8. Quality Management” from Head First PMP 3rd Edition.
4. “Chapter - 8. Quality Management” from PMP Exam Prep by Rita Mulcahy

Written by Sathish Babu:
Sathish Babu is working for Motorola Solutions as a Project Lead and having 11+ years of experience in Product, Project Management and Service Delivery in Telecom domain.

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