There are 7 basic quality tools that organizations can use to monitor and control their projects’ processes, and these tools are outlined in the PMBOK guide.
These tools can be applied to projects of all sizes and across all industries. Hence, they have become a staple in quality management. PMP aspirants need to understand what all 7 of these quality tools do and when to use them for their PMP exam.
In brief, the 7 Basic Quality Tools, or “7QC Tools”, are:
- Flow Charts
- Cause and Effect Diagrams
- Check Sheets
- Scatter Diagrams
- Control Charts
- Pareto Charts
Flow Charts help project managers understand the sequence of events. They help you visualize the relationships and dependencies between events. Building flow charts help the project team visualize a complex process in a simple way.
There are 3 components to the Flow Chart: events, arrows, and decision points. The events are connected by the arrow to show their sequence or order. Some events can also happen in parallel. The decision points, which are represented by diamonds, split events onto 2 separate path, and the path you go on depends on the decision you choose.
Project managers can make flow charts using tools such as MS Visio. Here is an example of a Flow Chart:
Histograms are graphs used to show frequency of distributions, or how often a value occur in a data set
Histograms are column charts that always have 2 variables. The goal is to measure one variable in the context of the other.
If the distribution of points of the dataset is normal, the chart will look like a bell curve with the most common occurrence being the mean. If the distribution is not normal, the graph will take different shapes depending on the data set.
Here’s an example of a histogram:
To create a histogram for your own project, download this free excel template here:
Cause and Effect Diagrams / Fishbone Diagrams / Ishikawa Diagram
This diagram got the name “fishbone” because the shape of this diagram resembles that of a fish skeleton. It was invented and popularized by Japanese professor Kaoru Ishikawa, the father of “quality circles.”
When problems arise on projects, organizations need a methodological way to determine what the root cause of the project is, and correct it immediately. Fixing the surface problem without addressing the root cause may just end up being a “band aid solution.”
The three main benefits of the cause and effect diagrams are:
- It promotes team work. The diagrams are usually done in brainstorming sessions and rarely completed in silos.
- It promotes structured analysis and thinking. The fishbone diagram must be MECE, or Mutually Exclusive Collectively Exhaustive. In other words, it must include all the causes to the problem and none of the causes can be a duplicate.
- It helps the project team visualize the root cause of the problem and eliminate bottlenecks.
Here’s an example of a cause and effect diagram:
If you want to build your own Ishikawa diagram for your own project, down this free excel template now:
4) Check Sheets
A check sheet (or checklist) is the most generic out of the 7 Basic Quality Tools. It is a form used to collect and organize data.
Before the digital revolution, check sheets were created with pen and paper. Nowadays, they are usually created and maintained with MS Excel, which can also extract more analysis with its graph and macro functions.
The check sheet ensures that all of the tasks are completed since the owner of the check sheet must enter a value next to each task. When he or she sees that there is a value missing beside a task, he or she will then promptly complete the missing task.
Check sheets are a quick and effective way to make sure that all tasks are completed for a process (it is kind of like a to-do list).
Here is an example of a check sheet:
To start creating your own check sheet for your projects, download this free excel template to help you get started:
A scatter diagram graphs a pair of numeric values (X, Y) onto a Cartesian plane (fancy word for a graph) in order to visualize the relationship between the two variables.
After all the (X, Y) pairs are inputted onto the graph, trend analysis is performed to understand:
- The correlation between Variable X and Variable Y
- How closely X and Y are correlated
As a project manager, understanding correlations between 2 variables can aid in your decision making. For example, if you found that there is a positive correlation between hours worked and accident occurrence, you may consider reducing the number of hours each employee works or hire more employees to get the job done.
Note: it is important, however, not to confuse correlation with causation.
Here is a picture showing the different types of correlations you can obtain from a scatter diagram:
To start building your own scatter diagram, download this free excel template to serve as a guide:
A Control Chart shows how a process changes over time. It is often used in manufacturing to monitor the health of processes (generally automated ones performed by machines).
Slight variations in processes are unavoidable and considered normal. The organization must determine how much variation they are willing to tolerate – this is typically 3 standard deviations from the mean.
The Upper Control Limit (UCL) and Lower Control Limit (LCL) is formed by adding and subtracting 3 standard deviations from the mean, respectively. (If your organization has a different method of determining the tolerance limits, use that instead.)
There are two ways that a process can be deemed “out of control”:
- The point of observation is above the UCL or below the LCL
- There are 7 consecutive points above or below the mean
The benefits of using control charts include:
- Monitoring the stability of a process
- Identification of irregularities in real time
- Reacting to special causes that make the process out of control
Here is an example of a control chart:
To start building your own, download this free excel template to get started:
Pareto Charts are bar charts that are organized based on priority. Pareto charts are useful because since project managers have limited time and money, they must prioritize issues and fix the ones that will make the biggest impact on the project.
On a Pareto Chart, the issues are listed in the X axis, and the number of occurrence of each issue is represented by the height of the bar. The issue that occurs the most often is on the far left, and the issue that occurs the least often is on the far right.
There is also a line graph that is built on top of the bar graph, which shows the percentage of occurrence of each issue.
Here is an example of a Pareto chart:
To build your own pareto chart, download this free excel template to get started faster:
The seven Basic Quality Tools are part of the Control Quality process.
You do not need to use all 7 Basic Quality Tools on all of your projects. As a project manager, you need to be aware of what is in your toolbox and pull out the appropriate tool in the appropriate situation.
Lastly, the excel templates for this article are obtained and managed by American Society of Quality. All credits go to them.