In simple words when we compare quality assurance with quality control the quality will be the defects prevention and the goal will be the zero defects for Quality Assurance where as quality will be defect identification and goal will be the process of control to reduce the defects for Quality Control.
§ In Quality Assurance deliverables are created which is performed by a manager or client. Checklist, project audits and methodology and standards are example of QA. Quality control is only about requirements. Quality assurance is basic and does not concern the specific requirements of the product being developed.
§ Whereas Quality Control is a process in which quality related activities are associated with the creation of project deliverables. Quality control is basically used to verify that deliverables are completed and correct. Inspections, deliverable peer reviews and the testing processes are the examples of quality control. Quality assurance actions are determined before production work begins and these activities are performed while the product is being developed. In contrast, Quality control actions are performed after the product is developed.
QA actions ensure that the process is defined and proper. Methodology and standards development are examples of QA activities. QA would focus on the process elements of a project and requirements are being defined at the proper level of detail. QC activities focus on the finding defects in the deliverables.
Typical QC steps:
· Problem Identification
The main outcome of the Problem Identification stage is to set the overall purpose and objectives of the risk assessment and to determine the likely data requirements
· Problem Analysis
To gather information that helps you determines the nature of a problem encountered on your system.
· Problem Correction
To correct the problem identified in QC process.
· Feedback To QA
Process of control to reduce the defects for Quality Control.
Typical QA steps:
· Data gathering
It is a frequent part of solving problems and satisfying curiosity
· Problem Trend Analysis
Based on number of problems occurring in the area under study
· Process Identification
Each process is identified with a unique name/number.
· Process Analysis
A process can be defined as "a logical series of related transactions that converts input to results or output" (Andersen 1999)
· Process Improvement
It is a series of actions taken by a Process Owner to identify, analyze and improve existing processes
QC Vs QA - Examples
| QC | QA |
| Walkthrough | Quality Audit |
| Testing | Defining Process |
| Inspection | Selection of tools |
| Checkpoint review | Training |
Is Testing a QA or a QC Activity?
Testing is an example of a QC activity, but there are others such as inspections.
The difference is that QA is process oriented and QC is product oriented.
Testing therefore is product oriented and thus is in the QC domain. Testing for quality isn't assuring quality, it's controlling it.
Quality Assurance makes sure you are doing the right things, the right way. Quality Control makes sure the results of what you've done are what you expected.
Example:
Let us consider an example to understand difference between software quality assurance and software control:
“Consider a software project that includes requirements, user Interface design and a SQL database implementation.
The SQA team would produce a quality plan that would specify any standards, processes and procedures that apply to the example project. These might include, by way of example, IEEE xyz specification layout (for the requirements), Motif style guide abc (for the user interface design) and Open SQL standards (for the SQL implementation). All of the standards processes and procedures that should be followed are identified and documented in the quality plan, this is done by SQA.
When the requirements are produced (in this example) the Software Quality Control team would ensure that the requirements did in fact follow the documented standard (in this case IEEE xyz). The same task, by SQC, would be undertaken for the user interface design and the SQL implementation, that is they both followed the standard identified by SQA. Later the SQA team could make audits to verify that IEEE xyz and not IEEE abc was indeed used as the requirements standard”.
In this way a difference between correctly implemented by SQA and followed by SQC can clearly be drawn.
The SQC definition implies software testing, as this is part of the project produces the required internal and external (deliverable) products definition for SQC. The term required refers not only to the functional requirements but also to the non-functional aspects of supportability, performance and usability etc. All of the requirements are Verified or Validated by SQC. For the most part, however, it is the distinction around correctly implemented and followed for standards, processes and procedures that gives the most confusion for the SQA and SQC definitions. Testing is normally clearly identified with SQC, although it is usually only associated with functional requirement testing.
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