Quality Assurance QA (PQA & SQA) vs Quality Control (QC)

Hoipt
TrueMoney Engineering
6 min readNov 29, 2019

Organizations often use the terms ‘Quality Assurance’ (QA) vs ‘Quality Control’ (QC) interchangeably. However, they both represent two very different aspects of quality management!

Understanding the exact meaning of these two terms under quality management is very important for every organization. This is because every client and customer’s top priority is always the quality of the product being delivered to them! Therefore, it is very essential to conduct both QA vs QC independently to increase the overall quality of their product.

First, let us look at the meaning of the different terms:

  • Quality-The quality of any product is determined by how well it meets the expectations and requirements of the customer. This means that the product must be free from errors, inconsistencies and lacking in some particular aspects. There are always some standards in terms of quality that need to be met in order to satisfy the requirements of the customers.
  • Assurance- It is the act of guaranteeing the customers, that the product being delivered fulfills their preferred quality level. It is done to give security that the end product will be error-free and will satisfy all requirements.
  • Control- It is the process of determining whether the end product matches all customer requirements or not. It involves testing and comparing the actual result with the desired result.
  1. Quality assurance (QA):

Quality Assurance is popularly known as QA Testing, is defined as an activity to ensure that an organization is providing the best possible product or service to customers. QA focuses on improving the processes to deliver Quality Products to the customer. An organization has to ensure, that processes are efficient and effective as per the quality standards defined for software products.

How to do Quality Assurance

  • Plan
  • Do
  • Check
  • Act

These above steps are repeated to ensure that processes followed in the organization are evaluated and improved on a periodic basis. Let’s look into the above steps in detail:

  • Plan — Organization should plan and establish the process related objectives and determine the processes that are required to deliver a high-Quality end product.
  • Do — Development and testing of Processes and also “do” changes in the processes
  • Check — Monitoring of processes, modify the processes, and check whether it meets the predetermined objectives
  • Act — Implement actions that are necessary to achieve improvements in the processes

An organization must use Quality Assurance to ensure that the product is designed and implemented with correct procedures. This helps reduce problems and errors, in the final product.

2. Quality Control (QC)

It is a Software Engineering process used to ensure quality in a product or a service. It does not deal with the processes used to create a product; rather it examines the quality of the “end products” and the final outcome.

The main aim of Quality control is to check whether the products meet the specifications and requirements of the customer. If an issue or problem is identified, it needs to be fixed before delivery to the customer.

QC also evaluates people on their quality level skill sets and imparts training and certifications. This evaluation is required for the service based organization and helps provide “perfect” service to the customers.

Quality Control has to complete after Quality Assurance.

3. Difference between Quality Control and Quality Assurance

Many people think QA and QC are the same and interchangeable but this is not true. Both are tightly linked and sometimes it is very difficult to identify the differences. Fact is both are related to each other but they are different in origins. QA and QC both are part of Quality Management however QA is focusing on preventing defect while QC is focusing on identifying the defect.

Examples of QC and QA activities are as follows:

The above activities are concerned with QA and QC of any product and not essentially software. With respect to software:

  • QA becomes SQA ( Software Quality Assurance)
  • QC becomes Software Testing.

Differences between SQA and Software Testing

Currenty QA is devided into 2 role: PQA (Process Quality Assurance) & SQA ( Software Quality Assurance)

SQA is considered as error checking when a product is configured. Others consider SQA to be a test of the intermediate output of a product, so that the product achieves consistency in the implementation process. In any case SQA is a direct product inspection. SQA’s work is often known as the job of a tester.

SQA incorporates all software development processes starting from defining requirements to coding until release. Its prime goal is to ensure quality.

PQA has 2 main jobs:

One is to build a system of processes for businesses (by applying existing management processes such as ISO or CMM or based on which to build a standard process for businesses).

The second is to perform the monitoring and inspection of the process implementation of each department, each project, from which information is gathered to make improvements to the good operating process.

Thus PQA and SQA are two completely different processes, with a reciprocal relationship, the input of PQA is SQA, and the input of SQA is PQA

In the cost of product quality, there are 3 subcategories:

  • Prevention cost
  • Control cost
  • Failure

According to some documents on the software production process (such as CMM), 1 dong spent on the 1st stitch will reduce 10 dong for the 3rd stitch, and 1 dong for the 2nd stitch will drop 3 dong for the 3rd stitch In order to do that, it is obvious that someone has to put that process into practice.

Many small and medium companies, they do not specify a clear PQA position, but QA Manager / Leader will be in charge of making the workflow between stakeholders. And once that process is approved by management, it will be maintained and applied to the project

Main tasks of PQA:

  • Proposing and devising product development process (processes) in accordance with the requirements of each project. These processes can be developed based on V-model or Agile (most Scrum Lean Development) or through the application of existing management processes such as ISO, CMMI.
  • Provide documents, forms, and guidelines to ensure product quality for all parts of the product development team.
  • Check, audit the execution of processes of the product group in the right process set out
  • Remind product development teams of compliance with the given workflow
  • Adjust and change processes to suit each product that the teams are making.

=> PQA is known as a “scrutiny”, the basic job is to specialize in “scrutiny” of software process.

In general, PQA does not require a deep knowledge of information technology (IT) like SQA because it is not related to the main product of a software project. However, the knowledge of PQA employees must be wide and deep enough to fully understand the work within the system they are managing, especially the ability to organize, logical and systematic. In addition, the communication skills and information exploitation of PQA staff are also important. In the company, there are many people, each of whom is good at a different field. PQA needs to know how to exploit to make use of that information for building a process system.

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