Every Software provider realises that delivering the best quality product is important for them. A software project should correspond with a range of requirements to be considered a high-valued product. People are often confused between the words Quality Assurance and Quality Control. Both of the terms are related with the phases of Software Development but are quite different. Before we dive deeper to understand the differences between Quality Assurance and Quality Control, let’s understand the term quality.
Quality is meeting the requirements and expectations of the customers and ensuring that the product is free of defects, irregularities, and bugs. It refers to a standard that the developer has to maintain to satisfy the needs of the users of the product. Let’s take an example- you go to a bakery shop to order cake. You order cake according to your requirements. For example, you would want a chocolate cake without egg and something written over it. The baker has to adhere to these requirements and bake the best quality cake for you. A software developer also has to meet requirements and expectations of the users of the product. The baker and the software developer try to deliver the best quality product.
What is Assurance?
Assurance is a promise given that the product will be delivered as per the expectations of the users of their product. It is generally given by an organisation or a firm. When we assure someone of something it provides them a feeling of security that we will deliver what we have promised.
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Quality Assurance is the promise made to deliver the best quality. It is implemented during the development phase of the software and it makes sure that the process, approach or technique involved is free from all defects and irregularities. The main goal of this process is to organise flawless software development and to protect it from mistakes. It is a preventive measure. Sometimes it is also termed as “zero defect approach”. It is used to identify flaws in the process and improve them beforehand. Quality Assurance is completed before Quality Control.
Some examples of Quality Assurance in Software Development Process are-
- Project Planning
- Preparing Flowcharts and schedules
- Selecting team members and training them
- Internal and External Audits
- Checklist inspection
- Process documentation
Advantages of Quality Assurance
- Improved Process Control
- An Internal system of checks and balances for the quality of products.
- Final cost reduction as mistakes are prevented at an early stage.
- It makes the work of the Quality Control team easier.
Disadvantages of Quality Assurance
- Time Consuming
- High Initial costs
- A lot of tasks has to be done to train staff
- Consumes a lot of resources
Control is a way of keeping something within certain limits. Quality Control focuses on controlling defects or bugs so that the product (software) is within the limits or expectations provided by the users of the product. It is used to detect defects at the end stages of software development cycle. Quality Assurance ensures that methods, processes, techniques and approaches used in the project have been implemented properly. The main purpose of the Quality Control process is to ensure that the product (software) meets the actual requirements of the users of the product. It aims to identify and fix the defects.
Quality Control is a reactive process. This is implemented during the testing phase. Quality Control is completed after Quality Assurance.
Types of Quality Control-
- Process Control: Makes sure that the processes within a company or an organisation are functioning properly.
- Control Charts: This type of Quality Control makes use of charts and graphs to ensure quality
- Product Quality control: It ensures the quality of end products.
Examples of Quality Control in Software Development Process-
- Testing and Debugging
- Peer reviews
Advantages of Quality Control
- The products build up goodwill or image which will ultimately increase sales.
- Helps in minimising cost by increasing efficiency.
- The developers can confirm that the product is in accordance set by the customers.
- Helps the business team to determine the estimated cost of the project beforehand.
- Reduces rejection rate and saves the cost of rejection.
Disadvantages of Quality Control
- Time consuming
- Requires lot of resources, especially human resources.
- There is a great deal of responsibility on the shoulders of the team responsible for quality control.
- Quality control also increases production cost.
Quality Assurance Vs Quality Control
QA (Quality Assurance) and QC (Quality Control) are slightly different terms but are tightly coupled. They both are important to deliver fine quality products and are used to complement each other. The differences arise due to the manner, phase, style, and the people who implement them.
Let’s look at some of the differences between QA and QC.
|Quality Assurance (QA)||Quality Control (QC)|
|1. It focuses on assuring that the product delivered will be of best quality.||It focuses on ensuring that the quality of the product assured is delivered.|
|2. It is implemented during the development phase of the software development.||It is not involved during the development phase.|
|3. It is not involved during the execution phase.||It is involved during the execution phase of the software.|
|4. It is used to check mistakes during early phases of the development.||It is used during the end phase to confirm that the software is defect free.|
|5. It is a proactive measure, which means that the developer controls the software along with the development.||It is a reactive measure, which means that the testing team reacts at the end phase to rectify the mistakes.|
|6. It is process oriented.||It is product oriented.|
|7. QA involves design of processes such as SOPs (Standard Operating Procedures) and project documentations.||QC involves testing of products to make sure they meet the provided standards.|
|8. It focuses on preventing quality issues.||It focuses on identifying quality issues.|
|9. QA focuses on the intermediate process in Software Development.||QC pays main focus on final products.|
|10. The result of QA activities is a roadmap for creating high quality products.||QC involves verification of products post manufacture and before distribution to the users.|
|11. QA involves all team members of the project.||QC generally involves the testing team of the project.|
|12. QA is a preventive technique.||QC is a corrective technique.|
|13. QA makes sure that what you are doing is right.||QC makes sure that there is not much difference between the expected output (software that the user expected) and actual output (software that has been produced).|
|14. QA is the technique of managing the quality of the product.||QC is a technique to verify the quality of the product.|
|15. QA is involved in the full software development life cycle.||QC is involved in the software testing phase of software development life cycle.|
|16. Example of QA is verification.||Example of QC is validation.|
- Both QA and QC are used to deliver quality products but QA is used during the development phase and QC is used during the execution phase.
- QA is used to prevent any defects and QC is used to detect defects.
- QA is performed in parallel with the project but QC is performed when the final product is ready.
- QA is a proactive measure and QC is a reactive measure.
- QA is performed before QC.
- Both are important to deliver quality products.
Let’s revisit our example of a bakery shop where we had ordered a chocolate eggless cake. The baker will follow a series of processes to prepare cake. Firstly, he will prepare eggless base by following a predefined set of procedures. Then he will add the required chocolate flavour and write the text that you told to write. In addition to this, he will follow certain techniques that he usually follows to enhance the flavour and taste of the cake. This is called Quality Assurance. Finally, when the cake has been made, he would check that the cake prepared is exactly what was ordered. This is called Quality Control.
Thus, QA and QC are two peas in the same pond, but they must not be confused with each other. One practice is insufficient without the other. If you only apply QA, you can organise the correct progress but the end product won’t be checked, which can be fatal for a company. On the other hand, if you apply only QC, the root of the problem cannot be identified and therefore the problem will never be eliminated. QA can identify mistakes that QC cannot and QC can identify mistakes that QA cannot.
Successful companies apply both these processes to maintain the quality of their products. The use of one does not necessarily eliminate or restrict the use of the other.
Frequently Asked Questions
1. What comes first, QA or QC?
Since QA is involved during the initial phase of the Software Development and QC is involved during the execution phase of Software Development, QA comes first.
2. What are the 4 types of Quality control?
The four types of Quality control are:
- Process control
- Control charts
- Product Quality Control
- Process control
3. What are Quality Techniques?
Quality techniques involve controlling activities and planning to ensure that the service or product is fit for the purpose of serving the needs and expectations of the users of the product.
4. What are the three main purposes of Quality Assurance and Quality Control Process?
Three main purposes of Quality Assurance and Quality Control-
- To make the product defect free
- To reduce the cost of errors
- To maintain brand reputation and increase sales
5. Is Quality Assurance Software Testing?
Quality Assurance is not related to the testing phase, Quality control is involved in the testing phase. Therefore QA is not software testing.
6. Why are Quality Control and Quality Assurance important?
Quality Assurance and Quality Control both are important to deliver the best quality of products to the clients or users of the product.