In the competitive landscape of modern business, quality isn't just a benchmark—it's the foundation of success. As organizations strive to improve processes, reduce defects, and enhance customer satisfaction, a suite of quality tools has emerged as their arsenal.  There are myriad quality approaches, but first, we should understand some concepts: What is the difference between quality assurance and quality control?

"It is not enough to do your best; you must know what to do, and then do your best,"
 ~ W. Edwards Deming

Quality Assurance and Quality Control

Both Quality Assurance and Quality Control are essential to achieving comprehensive quality management. However, these techniques work in different spaces with different objectives. Product development projects will often require quality management that includes both techniques.  To differentiate the two, we provide a short table below.



Quality Assurance (QA)

Quality Control (QC)


QA is a process-oriented approach that focuses on preventing defects in products and services through a systematic set of activities.

QC is a product-oriented approach that inspects and tests products and services to identify defects.


The main objective of QA is to improve development and test processes to prevent defects before they occur.

The main objective of QC is to identify and correct defects in the finished product.


QA is proactive, aiming to prevent defects and focusing on the process used to make the product.

QC is reactive, focusing on identifying defects in finished products.


QA activities include process documentation, process standardization, process improvement, and training.

QC activities include inspections, testing, and reviews to identify product defects.


QA is typically the responsibility of the entire team or organization. It focuses on improving processes across all phases of production.

QC is usually the responsibility of a specific team or individuals focused on testing products after they are developed.


QA is implemented throughout the development process, from the initial stages to the final delivery.

QC is generally implemented at the later stages of production, primarily during and after the assembly of products.

Tools and Techniques

QA uses tools and techniques such as audits, process definitions, and quality management systems.

QC uses tools and techniques like statistical quality control, inspections, and testing methods.


The outcome of QA is a reliable process or system that consistently produces quality products or services.

The outcome of QC is a product or service that meets quality standards and is free of defects.


QA focuses on building in quality and preventing defects in the process.

QC focuses on identifying and fixing defects in products or services.


By ensuring that both the processes (QA) and the products (QC) meet the highest standards, organizations can satisfy their customers and build a reputation for reliability and excellence. Integrating QA and QC into the quality management system provides a robust approach to continuous improvement and customer satisfaction.

Why Total Quality Management (TQM)?

We like TQM because the processes and tools are very straightforward. Benefiting from it does not require our team to be a group of engineers, as key team members are often not.  The process flow is clear, and the tools are moderately sophisticated, so learning when to use what tool will not require hours of training and years of experience using the techniques.  TQM also focuses on the team and the importance of those interactions.  The ease of use of the tools and techniques means anybody with a minimum of skill on the tools can analyze and provide insights to the rest of the team.

You can't manage what you don't measure."
~W. Edwards Deming


Total Quality Management (TQM): The Philosophical Backbone

At the heart of applying these tools effectively is Total Quality Management (TQM), a comprehensive management approach that focuses on long-term success through customer satisfaction. TQM is built on the foundation of quality pioneers such as W. Edwards Deming and Walter A. Shewhart.


Deming and the PDSA Cycle

W. Edwards Deming is renowned for his 14 Points for Management, which advocates for a systemic approach to problem-solving and continuous improvement. Deming also popularized the PDCA (Plan-Do-Study-Act) cycle, a four-step model for carrying out change. This cycle emphasizes a systematic approach to testing solutions, assessing results, and implementing what works.

If you can't describe what you are doing as a process, you don't know what you're doing.
~ W. Edwards Deming

The Deming Cycle, the PDSA cycle, is commonly associated with W. Edwards Deming. This cycle is a systematic and iterative approach to continuous improvement. The four steps in the PDSA cycle are:

  1. Plan (P):
    • Identify the problem or opportunity for improvement.
    • Set specific and measurable objectives.
    • Develop a plan to achieve the objectives.
    • Consider resources, potential obstacles, and the timeline.
  2. Do (D):
    • Implement the plan on a small scale.
    • Collect data and information during the implementation.
    • This step involves executing the plan in a controlled and limited manner.
  3. Study (S):
    • Analyze the data and results obtained during the "Do" phase.
    • Compare the actual outcomes with the expected outcomes.
    • Identify patterns, trends, and insights from the data.
  4. Act (A):
    • Based on the analysis, decisions about the effectiveness of the implemented plan should be made.
    • If successful, specifically, our predictions match the outcome and standardize the improved process.  We need to learn more if our predictions do not match the outcome. If improvements are needed, adjust the plan and repeat the cycle.


Shewhart's Contribution

Walter A. Shewhart, often considered the father of statistical quality control, introduced the concept of control charts and the importance of understanding process variation. His work laid the groundwork for the statistical tools used in TQM.

The Importance of the Team

A crucial element of TQM is the emphasis on teamwork. TQM posits that quality improvement is everyone's responsibility, from top management to front-line employees. Teams are empowered to make decisions and provide the training and resources to solve problems effectively. This collaborative approach improves processes and fosters a culture of continuous improvement.

TQM Tools

Within the TQM framework, the quality tools listed earlier are employed strategically to analyze and improve processes. TQM also introduces additional methodologies like benchmarking, strategic planning, and the Seven New Quality Tools, which include affinity diagrams and interrelationship digraphs.


Essential Quality Tools

When applied effectively, these tools can identify problems, analyze root causes, and implement corrective actions. Moreover, the philosophy of Total Quality Management (TQM) elevates these tools from mere techniques to integral elements of an organization's culture. Let's explore these tools and the principles of TQM that harness them for business excellence.


Flowcharts visually map out the steps of a process, making it easier to identify potential points of failure and opportunities for improvement.  Flowcharts are good illustrations of the project workflow, for example, how we intend to manage changes to the project.  This chart will provide a reference for the team members that is easy to understand.  In this way, the flowchart is an incarnation of the mental model of how the project wishes to handle changes.

These charts can also be used for project process improvement efforts. By visualizing the process, we can determine the weak points or areas for improvement. The visualization can give the team members a common view of what could be better.

Check Sheets

Check sheets are used to collect data in real time at the location where the data is generated. This simple yet powerful tool facilitates data analysis, especially for identifying patterns over time.  This is not for projects but work products such as early parts off the manufacturing line, such as the start of the line setup or ongoing quality improvement.

Cause-and-Effect Diagrams (Ishikawa or Fishbone Diagrams)

These diagrams help teams systematically explore potential causes of a problem. The visual representation categorizes potential causes into branches, aiding in root cause analysis. 


Pareto Charts

Pareto charts are based on the Pareto principle, which states that 80% of problems are often due to 20% of causes. These charts help prioritize problems or causes that need addressing.  Pareto charts help us determine where to place our focus.


Histograms are bar charts that display the frequency distribution of data. They are useful for understanding the variability of a process.  Histograms show the dispersion of an attribute.  For example, let's say we have been tracking the duration of vehicle preparation for systems testing. We have a task distribution ranging from three to 16 days; that would be the x-axis of the graphic below. On the y-axis, we see the number of occurrences of that duration; for example, we have what appears to have 14 occurrences of 10 days to prepare the vehicle for systems testing. 

The project manager would be ill-advised to suggest that a project have 10 days or less to prepare the vehicle without taking some compelling actions to improve.  Ideally, we would use this to set up our schedule, but when we realize that what we want does not match the pattern, we can then take some action to change the pattern for this project.


Control Charts

Control charts monitor process performance over time, distinguishing between normal process variations and variations that signal a process is out of control. This tool is more associated with operations than project management. However, it can be used for some operational aspects of the project; for example, we may keep a control chart on the key earned value management metrics. In this case, the control limits will not be calculated but derived from contractual expectations.  A control chart is also necessary if our project is to set up a manufacturing line to demonstrate capability.  In this way, the results frequently part, in our experience, of the contract closure.


Scatter Diagrams

These diagrams plot two variables against each other to identify potential relationships. They are particularly useful for exploring cause-and-effect relationships.  We may have heard the refrain; correlation is not causation; that is, of course, true. However, understanding there is some connection between variables provides us with some clues about what to expect and, equally important, where to continue our exploration.




Quality tools and Total Quality Management are not just about processes and methodologies; they are about a mindset that values customer satisfaction, continuous improvement, and teamwork. As organizations embrace these tools within the TQM framework, they pave the way for operational excellence and sustained success. Through the legacy of Deming and Shewhart and the practical application of quality tools, businesses can achieve incremental improvements and transformative changes in their quality management practices.

If you would like a deep dive into these topics, let us know.