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Quality Assurance and Quality Control

Author: Sophia
what's covered
In this lesson, you will learn how quality assurance (QA) and quality control (QC) work together to ensure project deliverables meet established quality standards. You’ll explore how QA focuses on preventing defects, how QC identifies and corrects them, and how common quality tools are used to improve processes and outcomes.

Specifically, this lesson will cover the following:

Table of Contents

1. What is Quality Assurance and Quality Control?

QA and QC are both components of the project quality process, each playing a distinct but complementary role in ensuring successful project outcomes. If you recall, we discussed metrics and KPIs in our last tutorial. Once the metrics and KPIs are set, QA and QC are the processes used to make sure the metrics, KPIs, and company goals are met.

Quality assurance (QA) is important because it focuses on the processes used to create deliverables, aiming to prevent defects before they occur. By establishing standards, conducting audits, and promoting continuous improvement, QA helps teams maintain consistency, reduce risks, and build quality into every phase of the project. This proactive approach not only improves efficiency but also enhances stakeholder confidence in the project’s ability to meet expectations.

On the other hand, quality control (QC) is important because it ensures that the final deliverables meet the defined quality standards and are free from defects. QC involves inspecting, testing, and validating outputs to detect and correct any issues before they reach the customer or end user. This reactive approach helps safeguard the integrity of the product and ensures that it is fit for use.

Together, QA and QC create a comprehensive quality management system that supports both process excellence and product reliability, ultimately contributing to project success and customer satisfaction.

Let’s look at each in more detail.

terms to know
Quality Assurance (QA)
The processes used to create deliverables, aiming to prevent defects before they occur.
Quality Control (QC)
Inspecting, testing, and validating outputs to detect and correct any issues before they reach the customer or end user.


2. Quality Assurance (QA)

The purpose of QA is to provide confidence to stakeholders that the project will deliver outputs that are fit for its purpose. It involves activities such as process checklists, quality audits, and performance reviews to verify that the project is following established procedures and best practices. By maintaining consistent standards and identifying areas for improvement, QA helps reduce rework, increase efficiency, and ensure customer satisfaction.

Below is a list of common QA tools and techniques used in project management and product development:

Tool Purpose Example
Checklists To ensure all required steps or standards are followed during processes A retail store uses a daily opening checklist to ensure all required tasks are completed, such as turning on the lights, checking the cash drawers, restocking the front displays, and verifying that the POS system is working before customers arrive.
Flowcharts To visualize processes to identify inefficiencies or potential quality issues A clothing retailer creates a flowchart showing the return and refund process. The chart helps visualize each step, including receiving the returned item, inspecting it for damage, issuing a refund, and updating the inventory, so bottlenecks or redundant steps can be identified and improved.
Control charts To monitor process stability and detect variations over time A coffee shop tracks the temperature of brewed coffee throughout the day using a control chart. If the temperature starts to drift outside the acceptable range, it signals that the coffee machines may need calibration or maintenance.
Pareto analysis (also known as the 80/20 rule) To identify the most significant causes of defects or problems since most of the effects come from 20% of the causes A shoe retailer discovers that 80% of customer complaints come from 20% of their product lines. By focusing on improving the quality or fit of those specific shoes, they can significantly reduce overall complaints.
Fishbone diagrams (also called cause-and-effect diagrams) To analyze the root causes of quality issues A bakery uses a fishbone diagram to find out why cakes are frequently overbaked. Causes are grouped into categories, like equipment (oven thermostat issues), methods (inconsistent baking times), people (staff training), and materials (flour moisture levels).
Histograms To display the frequency distribution of data to spot trends or anomalies A call center creates a histogram showing the number of customer calls handled per hour. The chart reveals that call volume spikes between 9 and 11 AM, prompting managers to adjust staffing schedules.
Scatter diagrams To show the relationships between two variables to identify correlations A furniture company plots a scatter diagram comparing customer satisfaction scores with delivery times. The diagram shows a clear, negative correlation—longer delivery times tend to reduce satisfaction.
Benchmarking To compare performance against industry standards or best practices A hotel compares its guest satisfaction ratings and check-in times against a top-performing competitor. By studying the competitor’s streamlined digital check-in system, the hotel identifies opportunities to enhance its own process.
Statistical sampling To select representative samples for inspection or testing A cosmetics manufacturer takes a sample of 50 lipsticks from every production batch to inspect the color consistency and packaging quality rather than testing all 10,000 units produced that day.
Quality audits To independently review processes and compliance with standards A restaurant chain conducts an internal quality audit of food safety practices. An independent auditor reviews sanitation logs, employee hygiene practices, and temperature control records to ensure compliance with health standards.


IN CONTEXT

Pareto Analysis

Imagine you manage a retail clothing store and review 2 months’ worth of customer complaints. After categorizing them, you find the following correlation between the complaints and their causes:
  • 40% due to long checkout lines
  • 24% due to out-of-stock items
  • 16% due to unhelpful staff
  • 8% due to messy fitting rooms
  • 6% due to incorrect pricing
  • 6% due to poor store layout
Applying Pareto analysis, you’d focus on improving checkout efficiency, inventory management, and staff training first since those top three issues make up 80% of the total complaints.

In project management, QA is about building systems and processes that prevent issues and mistakes before they happen to deliver a product or service that meets the needs of the stakeholders. QC is what happens after something is produced. Let’s address that next.


3. Quality Control (QC)

key concept
Quality control (QC) in project management is the process of monitoring and inspecting project deliverables to ensure they meet the defined quality standards and requirements. Unlike QA, which focuses on preventing defects through process improvement, QC is product oriented and aims to identify and correct defects in the outputs before they reach the customer or end user.

QC involves comparing the actual results against the expected outcomes and taking corrective actions when discrepancies are found. Effective QC helps reduce rework, improve customer satisfaction, and ensure that the final product is reliable, functional, and fit for purpose.

A flowchart depicting a quality control process. It begins with ‘Perform Inspections’, which flows into ‘Detect Defects’. From there, two paths emerge. One arrow leads to ‘No Defects’, which then flows to ‘Success!’ The other arrow leads to ‘Control Outputs’. From ‘Control Outputs’, an arrow loops back to ‘Detect Defects’, forming a continuous cycle for ongoing inspection and correction. The diagram highlights how defects are either corrected or lead to successful results if none are found.

Below is a table summarizing key QC activities commonly used in project management, including testing, inspections, reviews, and statistical analysis:

Activity Description Purpose Example
Testing Execution of a product or component to identify defects or verify functionality To ensure the product works as intended Running unit tests on software features
Inspections Formal examination of deliverables or processes to detect errors or nonconformities To catch defects early and ensure compliance Inspecting construction materials for cracks
Reviews Systematic evaluation of documents, code, or designs by peers or experts To identify issues and improve quality early Conducting a design review for a new product
Statistical analysis Use of data-driven techniques to monitor and control quality performance To detect trends, variations, and root causes Applying control charts to monitor defect rates

Think of QC as the safety net for the project. Defects and mistakes are found so that the quality meets the needs of the stakeholders and users.

Finally, let’s look at two of these tools in action.


4. Tools in Action

Let’s look at two examples of quality tools used in actual scenarios.

EXAMPLE

Our first example is that of a Pareto chart. In this scenario, our store manager has performed an analysis of problems impacting the store over the past quarter and prepared this Pareto chart, highlighting the most frequent issues affecting store performance:

A Pareto chart showing the number of occurrences for five issues. ‘Stockouts’ have 120 occurrences, ‘Pricing Errors’ 85, ‘Poor Customer Service’ 60, ‘Delayed Deliveries’ 45, and ‘Inventory Mismanagement’ 30. A cumulative percentage line rises across the bars, showing that ‘Stockouts’ and ‘Pricing Errors’ contribute most to the total issues.

Insights from the chart:

  • Stockouts are the most frequent issue, accounting for a significant portion of problems. A stockout occurs when an item is completely out of inventory and unavailable for sale or use when needed.
  • Pricing errors and poor customer service follow, contributing notably to overall disruptions.
  • The cumulative percentage line shows that addressing the top two or three issues could resolve over 70% of the problems—demonstrating the Pareto analysis (80/20 rule).
Given that the two main issues appear to be stockouts and pricing errors, the manager then knows they should focus on those two elements first. So, they may work on better management of their inventory and also develop better processes for setting the price of items in the store.

EXAMPLE

Our next example is a small manufacturing firm trying to identify the assignable causes of variations in its manufacturing line. They decided to use a fishbone diagram (or cause-and-effect diagram) because it can provide them with various causes of an issue and help them get to the root causes. They assemble a team that identifies six possibilities that may be causing the variation issues:
  • Low-quality raw materials
  • Power fluctuation
  • Ambient temperature
  • Worker absenteeism
  • Poor training
  • Old equipment
Each of these possibilities is organized into a fishbone diagram:

A fishbone diagram showing possible causes of a problem. The main categories leading to the problem are ‘Low-quality raw material’, ‘Power fluctuation’, ‘Ambient temperature’, ‘Worker absenteeism’, ‘Poor training’, and ‘Old equipment’. Each category lists contributing factors such as poor inspection, overloaded circuits, inadequate onboarding, poor scheduling, and lack of preventative maintenance. The diagram’s structure resembles a fish skeleton with the problem labeled at the head.

To use a fishbone diagram, first you’d write the potential causes of the variation issue, as we’ve done here. Then, you’d look at the subcauses for each, as we did with power fluctuation. This helps us to see the potential root causes of an issue, so we can resolve the issue.

big idea
Both QA and QC serve a distinct purpose in ensuring successful project outcomes. QA is a proactive, process-oriented approach that focuses on preventing defects by improving and standardizing the methods used throughout the project. In contrast, QC is a reactive, product-focused process that involves inspecting and testing deliverables to identify and correct defects. QC ensures that the final outputs meet the defined quality requirements and are fit for use.

summary
In this lesson, you learned how quality assurance (QA) and quality control (QC) work together to ensure that project deliverables meet established quality standards. You explored how QA focuses on preventing defects through proactive process improvement, audits, and continuous monitoring, while QC focuses on detecting and correcting defects in deliverables through testing, inspections, and reviews. You also examined several QA and QC tools and techniques—such as checklists, Pareto charts, and fishbone diagrams—and saw these tools in action through real-world examples. By the end, you understood how QA and QC complement each other to create consistent, high-quality project outcomes.

SOURCE: THIS WORK IS ADAPTED FROM (1) PRESSBOOKS "NSCC PROJECT MANAGEMENT” BY ADRIENNE WATT. ACCESS FOR FREE AT WWW.PRESSBOOKS.ATLANTICOER-RELATLANTIQUE.CA/PROJECTMANAGEMENT/ AND FROM (2) SASKOER "PROJECT MANAGEMENT: A STRATEGIC APPROACH" by CARMEN REAICHE. ACCESS FOR FREE AT WWW.SASKOER.CA/STRATEGICPROJECTMANAGEMENT/. LICENSING (1 & 2): CREATIVE COMMONS ATTRIBUTION 4.0 INTERNATIONAL

Terms to Know
Quality Assurance (QA)

The processes used to create deliverables, aiming to prevent defects before they occur.

Quality Control (QC)

Inspecting, testing, and validating outputs to detect and correct any issues before they reach the customer or end user.