Quality assurance and quality control

Definitions

  • QA is a set of activities for ansuring quality in the processes by which products are developed

  • QC is the set activities for ensuring quality in products. The activities focus on identifying defects in the actual products produced.

Focus on

  • QA aims to prevent defects with a focus on the process used to make the product. It is a proactive quality process.

  • QC aims to identify (and correct) defects in the finished products. Quality control, therefore. Is a reactive process.

Goal

  • The goal of QA is to improve development and test processes so that defects do not arise when the product is being developed.

  • The goal of QC is to identify defects after a product is developed and before it’s released.

How

  • QA Establish a good quality management system and the assessment of its adequacy. Periodic conformance audits of the operations of the system.

  • QC Finding & eliminating sources of quality problems through tools & equipment so that customer’s equipment are continually met.

What

  • QA Prevention of quality problems through planned and systematic activities including documentation.

  • QC The activities of techniques used to achieve and maintain the product quality, process and service.

Responsibility

  • QA Everyone on the team involved in developing the product is responsible for quality assurance

  • QC Quality control is usually the responsibility of a specific team that tests the product for defects.

Example

  • Verification is an example of QA

  • Validation/software testing is an example of QC

Statistical techniques

  • Statistical tools & techniques can be applied in both QA/QC when they are applied to processes (process inputs & operational parameters), they are called Statistical process control (SPC); & it becomes the part of QA .

  • When statistical tools & techniques are applied to finished products (process outputs), they are called as Statistical quality control (SQC) & comes under QC .

As a tool

  • QA is a managerial tool

  • QC is corrective tool

Orientation

  • QA is process oriented

  • QC is product oriented