Earlier in this learner resource, we said that quality assurance (QA) and quality control (QC) are closely linked, but each has a different focus. In QC, deliverables are inspected to identify defective products. In QA, quality is built by analysing and auditing the processes used. We looked at QA in topic 3.
By the end of this topic, you will understand:
- balancing QA and QC activities
- activities for QC and quality evaluation
- continuous improvement
- quality management review and reporting
- project evaluation and review processes.
Carrying out QC activities is critical for quality control because they help prevent defective deliveries and products from reaching customers. Poor or too little QC can lead to customer dissatisfaction, repair and replacement costs, possible project over-runs and reorganisation, and, in worst cases, high costs, injuries or even death.
Too big a reliance on QC over QA can mean costly inspections and tests are carried out instead of fixing process problems. When there is a balance between QC and QA activities, QC can monitor the results of QA efforts, measure quality performance levels and recommend corrective actions. Balancing QA and QC during a project gives a basis for using continuous improvement throughout the project’s life cycle.
Watch
Quality Control Explained | Production & Operations (4:57). Watch the following YouTube video by tutor2u focusing on inspection to identify sub-standard products and services.
Activities for quality control (QC) and evaluating quality include:
- Carrying out testing and inspections to ensure deliverables meet required quality requirements
- Identifying variances in quality and taking required action
- Carrying out continual improvement
- Reporting
- Identifying lessons learned
Quality Control Plan
A quality control plan (QCP) is a written set of procedures, activities, tests, inspections and quality-related checkpoints needed to control the quality of the deliverables from a project. The QCP may be developed as part of preparing the quality management plan and confirmed in the QC phase.
QC Steps and Tasks
There are four steps in QC:
| QC Step | Description |
|---|---|
| Setting benchmarks |
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| Appraising conformance |
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| Acting when necessary |
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| Planning for improvements |
|
Resource
Quality Control Activities – Ensuring that Deliverables Comply with Quality Requirements, at My Management Guide.
Relationship Between Error Identification Times and Fixing Costs
QC emphasises the principle: the earlier errors are identified and eliminated, the better. Research across industries has identified differences in cost (time and money) depending on when errors are fixed.
Each error costs:
- 10 times more to fix in production than in development
- 100 times more if the error reaches the customer
Example costs for fixing an error in other parts of the project process are:
| Process point where the error is fixed | Cost to fix |
|---|---|
| Scope | $1 |
| Design | $10 |
| Prototype | $100 |
| Production | $1,000 |
| Marketplace | $10,000 |
QC is not about checking quality only at the end of production. Instead, three commonly used quality inspection types are carried out at different points.
Types of quality inspections
There are three commonly used types of quality inspections. In manufacturing, these may be carried out by internal or external inspectors. External inspectors may represent the customer or a regulatory body.
The three types, or points, of inspection are:
| Quality Inspection Types (or Points) | Description |
|---|---|
| Pre-production inspection |
|
| During production inspection (‘in-line’ or ‘in-process’ inspection) |
|
| Pre-shipment inspection(final random inspection) |
|
Watch
What Is A Quality Inspection? (15:06). Watch this YouTube video by Quality Inspection, introducing quality inspections to importers using foreign manufacturers to produce their products.
Resource
See more details about quality inspections and pitfalls for buyers related to inspections at the following link:
QC Basics: What is a Quality Inspection? Context, Tools & Template, by Renaud Anjoran at QualityInspection.org
Statistical sampling
Statistical sampling selects a random number of items from a batch to inspect them for defects and conformance.
Inspection reports
A QC inspection report usually includes the following sections:
Conformity to specifications:
- Components
- Assembly
- General appearance
- Labelling
- Packaging and packing
On-site tests and measurements:
- Description of tests carried out
- Equipment used
- Result, metric or measurement required
- Measurements of cartons and products (size and weight)
- Findings
Production status:
- Whether all products were available and all were counted
- Findings for other relevant questions, for example, when will full production be finished etc.? How many production lines are working on the products?
Visual defects for product and packing:
- Listed, described and categorised as critical, major and minor
- Total numbers compared to required limits and standards
- Photographs indicating the size of defects and position on the product
Appendix photos:
- List of photographs taken. They should include acceptable products/packaging as well as defects
- Description of the angle of each photo (for comparison across inspection reports)
Resource
See more details about inspection reports and sample reports.
Inspection checklists
The project team develops inspection checklists to assist inspectors by clearly explaining quality requirements. Checklists are essential when raw materials and other supplies are inspected. Checklists may be developed in quality planning and included in the QMP.
Resource
See more details and examples of inspection checklists.
Quality testing
Quality testing involves testing a product at a certified laboratory to confirm compliance with relevant standards and regulations. Testing can help buyers to check which raw materials have been used, whether a product contains hazardous chemicals or if there is a safety risk related to a product. Early testing can help prevent or fix errors sooner. In addition, testing laboratories can provide product safety and performance certification.
Resource
See more about quality testing and the differences between testing and inspection.
Testing in the computer industry
In the computer industry, testing is carried out as part of software development and system implementation. Test plans and test cases are developed during quality planning or in preparation for quality control. These describe how tests should be conducted and how screens, fields and functionality should be used during the test. The benefits of developing test plans include:
- Setting clear goals and expectations for the testing process
- Better control of the testing process
- Clarifying the time, effort and cost of testing
Resource
See more about preparing for software testing, including developing test plans.
Peer reviews
In peer reviews, work is checked by other professional equals (peers) to ensure that requirements are met. Peer reviews are used in many occupations because peers can quickly identify each other’s errors. For example, a team of coders in software development may meet and check the code line by line to find errors. As well as finding errors and making corrections, peer reviews also suggest improvements.
Resource
Find out about peer reviews in production engineering.
Customer input for QC
Customer feedback, complaints and requests about products are valuable input for QC. A process is needed for gathering this input, responding to customers quickly, investigating complaints and fixing product errors identified by customers.
Manufacturers of consumer products may conduct customer surveys at regular intervals, using tools such as focus groups, phone and face-to-face interviews and door-to-door or street interviews. Organisations may hire external marketing consultants to carry out this work or use an in-house marketing team.
Tools used in QC
Seven tools are commonly used in QC activities and can also be used in QA. These were discussed in chapter 2.9 of this learner guide. Tools may be selected for a project during quality planning. Organisations and individual professionals may have preferences for which tools are used.
The seven tools are:
- Flow charts
- Check sheets
- Cause and effect (fishbone) diagram
- Pareto charts
- Control charts
- Histograms
- Scatter diagrams
Resource
Review information about these tools and see a sample of each.
More about QC tools and methods in manufacturing
In industries which manufacture products such as cars, trains, aeroplanes etc. QC is critical because of the risk of injury and loss of life and for minimising product recalls. Commonly used QC tools in these industries include:
- Statistical process control (SPC): used to identify and solve problems before products leave the production facility
- Six sigma: uses five key principles to ensure that products meet customer needs and have zero defects
These tools are used alongside Lean methodologies and tools like total productive maintenance (TPM), 5S and Kaizen to eliminate most, if not all, defects:
- TPM: uses maintenance programs and operator training to eliminate downtime, defects and accidents
- Kaizen: empowers workers to find and solve problems on a daily basis, helping to eliminate problems at their source
- 5S: organises and standardises workplaces, which improves processes and eliminates errors
QC is carried out at two levels:
- Operators: monitor the manufacturing process and ensure that there is little variation
- Engineers: monitor the product design for issues and fix problems immediately16
Resource
Find out more about QC in manufacturing from Graphic Products.
Continuous (or continual) improvement is the idea that organisations should carry out incremental improvements to products, services and processes.
Principles of continuous improvement include:
- Improvements are based on small changes, not just major paradigm shifts or new inventions
- Employee ideas are valuable
- Incremental improvements are typically inexpensive to implement
- Employees take ownership and are involved in the improvement
- Improvement is reflective and needs constant feedback and open communication
- Improvement is measurable and potentially repeatable
When continuous improvement becomes part of company culture, difficult challenges can be tackled efficiently and cost-effectively. Improvements in technology can achieve results quickly and sustain long-term success. 17
Lean continuous improvement model
The Lean continuous improvement model is part of the Lean approach to project management. Lean continuous improvement tries to improve every process in an organisation by improving those that provide the most value for customers and removing activities that are not needed, called process wastes.
Lean methodology has been combined with other methodologies such as Six Sigma, which is applicable to cultural change, and the Hoshin Kanri planning process, which ensures that company strategy is executed across the whole organisation.
Resource
Find out more about Lean principles for continuous improvement.
PDCA-PDSA cycle for continuous improvement
Dr W. Edwards Deming was an American scholar and teacher in the 1900s, specialising in statistical variance, systems and systems thinking, and human psychology. He consulted with major corporations and governments and developed a model for transforming management, manufacturing and service delivery. After the Second World War, Deming assisted Japan in transforming its industry. His theories and teachings for continual improvement changed perceptions about quality, management and leadership.
The Deming wheel, or cycle, of Plan-Do-Check-Act (PDCA) (also known as Plan-Do-Study-Act [PDSA]), is a quality improvement process for testing, analysing and gaining knowledge for continual improvement of a product, process or service.
| Describe the objective, change being tested, predictions, needed actions, plan for collecting data. | Implement the plan. Run the test. Describe what happens. Collect data. | |
 |
||
| Decide what is next. Make improvements and changes to start another cycle. | Monitor and evaluate the plan implemented. Analyse data. Compare outcomes to predictions. | |
Resource
Find out more about Dr Deming and his model for continual improvement.
Case Study
Contract for QA and QC Review Services
Mika and Nate are directors of a small online publishing company offering services in online content creation, instructional design and training design and development. They were invited to submit a proposal to provide QC services for a national organisation to assist with implementing an online learning system. These services included:
- Providing processes and standards for a remote team of content developers
- On-going review of training program content and compliance with development specifications
- Liaison with the developers and the organisation’s IT department to ensure approved training programs were uploaded and working as required
A five-year contract was awarded, and Mika and Nate put together a team of six contractors working from home to carry out the QC review. Mika was responsible for client liaison, project administration and supervising the instructional design component. Nate supervised the content development review work. Over the five years, the QC review team oversaw the development of all online training for the organisation, including compliance, induction and company information programs. At the end of the five-year contract, Mika and Nate assisted the organisation in bringing the QC review system in-house.
The quality management plan should include details about quality management review and reporting, including:
- Frequency of review meetings
- Who will participate
- How will reporting be carried out
- Agenda for QMR meetings, for example:
- Presentation of all quality metrics data collected
- Comparison to the previous reporting period
- Status of product and process repeatability
- Recommended action to correct faults
- Requirements for initiating a change request
- Requirements for updating project documentation after each review period
The project or quality manager prepares a quality report for presentation at each review meeting. This report may be included in the overall project management report. Contents of a quality report vary depending on the industry and project but should include the following:
- Quality management issues
- Recommendations for corrective action
- Summary of findings from quality activities in the period
- Recommendations for improvements
Project evaluation
Quality evaluation considers variations in quality by measuring the average value across a group of products or procedures. Variations must be reviewed over time to compare the QMP objectives with the actual project performance.
Variance
All sets of measured data are subject to a degree of variation. Even the slightest variation should be recorded, as it provides information about how close, and importantly, how far, the product is from standards and requirements.
Variance classification is a critical activity in quality management. In quality control, there are two sources of variation:
| Common cause variation | Special cause variation |
|---|---|
|
|
Watch
SM14 Variation Causes Common vs Special (9:33). Watch the following YouTube video by StatStuff reviewing the two main types of variation that can affect a process.
Identification of common and special causes provides crucial data that informs quality management. Quality improvement requires knowledge about the source of issues. Knowing the cause and type of variation helps determine the best actions to repair and improve the process or product. A control chart distinguishes whether the variation is a common cause or a special cause variance.
Post-implementation review
Carrying out a post-implementation review (PIR), or post-project review, is a project management responsibility as part of project closure. It identifies project successes, deliverables, achievements and lessons learned from items that may not have worked out as planned.
A PIR report may summarise the following:
- Project gap analysis
- Quality of deliverables
- Stakeholder satisfaction
- Costs and workloads
- Benefits
- Lessons learned
Input for preparing a PIR may come from reviewing all documentation generated by the project, reviewing the results of customer surveys and talking with project team members. A post-project review meeting should facilitate a systematic overview of the process and how everyone might work together to improve it. Hiring an independent facilitator may help in collecting review input.
When the review report is ready, share the findings and ensure that everyone involved has access to it.
Resource
Find out more about PIR and the contents of a PIR report.
Documenting lessons learned
The information gained from the evaluation and review process provides the knowledge for lessons learned. The documentation of lessons learned provides future project teams with the data to design more effective and efficient projects. Documentation of lessons learned should occur throughout the lifecycle of each project. Progressive evaluation and documentation are essential during long-term and large-scale projects to assist those involved in remaining on track and addressing issues as they occur. Maintaining a formal document also helps achieve quality targets aligned with external and internal quality standards.
Commitment from senior-level management is critical for a lesson-learned program to be successful. Support and resources for continual improvement occur through regular metric reviews and the implementation of best practices. Formal documentation, with concise and clearly-defined recommendations, will secure management involvement with quality management during the project lifecycle.
A lesson-learned survey can be developed to collect feedback and ideas from project team members during and at the end of a project. A comprehensive PIR can identify critical information to successfully plan and manage future quality projects.
Resource
Review suggested questions for a lessons-learned survey.
Implementing improvements
Quality improvement involves taking specific actions, such as:
- Remedial action: amends quality variations that occur during the project lifecycle
- Corrective action: minimises disruption and damage to the quality objectives throughout the project
- Defect repair: happens after production and delivery
- Preventative action: informs future projects of potential issues
All of these actions are considerations for continual improvement and project quality management.
Every organisation, no matter how large or small, benefits from ongoing quality management. Quality management processes throughout a project enable continual improvement to accomplish quality standards and desired objectives. At the end of every project, it is wise to conduct a post-implementation review (PIR) to evaluate project success and gather data for lessons learned.
