Quality Assurance and Quality Control


Quality Assurance and Quality Control

 In present day environment, ‘Quality’ is the focus area for the management of every organization for achieving the success. Quality plays a substantial role on the bottom line of the organization. Two terms related to quality that are frequently being used in the Total Quality Management (TQM) and different quality related standards such as ISO 9001 etc. are ‘Quality Assurance’ (QA) and ‘Quality Control’ (QC). Both QA and QC are the part of one circle under quality management techniques. QA concentrates on defect prevention while QC deals with the detection. This is shown in Fig 1.

Circle of QA and QC

Fig 1 Circle of QA and QC

 The terms of QA and QC are closely related to each other. Both the terms also have the same objectives.  In fact both QA and QC complement each other. They are so interlinked and inter-dependent that many persons find it difficult to distinguish them. QA is process oriented and focuses on defect prevention, while QC is product oriented and focuses on defect identification. There exists a lot of confusion in many organizations with respect to these two terms and the activities associated with them.

The intended purpose of both QA and QC is to make the product defect free and ensure that it conforms to the requirements of product specifications. In fact both of these terms have got common objective. However the approach to achieve the objective is different. The route followed by both is also different for achievement of the objective.

QA still has QC at its core to control the quality of service/product, but it goes beyond mere testing or inspection to also consider related activities or processes (such as training, document control and audits) that may be resulting in defects further down the line.

Both QA and QC are essential for an organization for the production and supply to the customer the products which are meeting his requirements while conforming to the specifications. Organizational management is to ensure that the employees at the production level take the primary responsibility for implementing the appropriate QA, QC and testing activities.

The amount of attention provided to QA and QC is a function of the organizational risk and reflects the maturity of the organization. As organization matures, management and employees implements the proper QA and QC approaches as a matter of habit. When this happens then the organization is at minimum risk.

The two terms QA and QC are described below.

Quality assurance

QA is a complete system to assure the quality of products or services. It is not only a process, but a complete system that also includes control. QA is process oriented and ensures that right things are being done in a right way. It is a way of management. QA is an effective tool in the hands of the management to mitigate risk.

QA is developed from the realization that quality can be improved by looking ‘further up the line’.  It is aimed at preventing nonconformities/defects.

Various definitions of QA are as follows.

  • ISO 9000 defines QA as ‘A part of quality management focused on providing confidence that quality requirements will be fulfilled’.
  • QA is ‘All the planned and systematic activities implemented within the quality system that can be demonstrated to provide confidence that a product or service will fulfill requirements for quality’.
  • QA is defined as a procedure or set of procedures intended to ensure that a product or service under development (before work is complete, as opposed to afterwards) meets specified requirements.
  • QA is fundamentally focused on planning and documenting those processes to assure quality including things such as quality plans and inspection and test plans.
  • QA is a system for evaluating performance, service, of the quality of a product against a system, standard or specified requirement of the customers.
  • QA is a system of checks designed to ensure that products are free of faults.
  • QA is a set of activities designed to ensure that the development and/or maintenance process is adequate to ensure a system will meet its objectives.
  • QA is the process of managing for quality.
  • QA is defined as a procedure or set of procedures intended to ensure that a product or service under development (before work is complete, as opposed to afterwards) meets specified requirements.
  • QA is a set of activities for ensuring quality in the processes by which products are developed.
  • QA is the process or set of processes used to measure and assure the quality of a product.
  • QA attempts to improve and stabilize production (and associated processes) to avoid, or at least minimize, issues which led to the defect(s) in the first place.

QA process is a proactive process. The purpose of QA is to prevent the defects entering into the product during the stage of its manufacturing. Hence QA is process oriented which focuses on the defect prevention. It is done through a focus on the process used to make the product.

QA is a function of the management to assure the quality of the products or services to the customers. It is not only a process, but a complete system which also includes control. It is done by establishing a good quality management system and the assessment of its adequacy, conformance audit of the operation system, and the review of the system itself.

QA is the prevention of quality problems through planned and systematic activities including documentation. The documentation sets guidelines that are necessary to be implemented to assure the quality of the product after production conforming to the specification, other stated requirements and expectations from the product. QA activities start in the very beginning of the production cycle, even at the planning stage of the production.

QA is achieved by adequately developing and implementing the QA process. QA process is carried out by accurately defining the manufacturing process of the product, making quality plans, inspection and check plans at the intermediate stages of manufacturing, quality audit plans, use of measurement tools and defect tracking tools, use of statistical tools for statistical analyses, and training of personnel in the selected methods and processes.

By the adaption of process based approach of QA, an organization can reduce drastically the product rejection rate, avoid the rework and improve the product yield. This helps in the cost management of the organization.

QA is not the responsibility of selected persons or of a department but it is the responsibility of the entire team of persons who are even remotely connected with the production process.

 Quality control

QC is a process that measures and determines the quality level of products or services. It is the activities or techniques used to maintain the product quality, process and service. It is the way of ensuring that the results of a process are the same as was expected. It emphasizes testing of products to uncover defects and reporting to management who make the decision to allow or deny product release.

QC consists of finding and eliminating causes of quality problems through tools and equipment so that the requirements of the customer are met on a continuous basis.

QC is a product based approach. It is concerned with the operational activities and techniques that are used to fulfill the requirements of quality.

QC is the most basic level of quality.  It starts with activities whose purpose is to control the quality of products or services by finding problems and defects.

Various definitions of QC are as follows.

  • ISO 9000 defines QC as ‘A part of quality management focused on fulfilling quality requirements’.
  • QC is the process involved within the system to ensure job management, competence and performance during the manufacturing of the product or service to ensure it meets the quality plan as designed.
  • QC is defined as ‘The operational techniques and activities used to fulfill requirements for quality’.
  • QC is the physical verification that the product conforms to the planned arrangements by inspection, measurement etc.
  • QC is the process of meeting products and services to consumer expectations.
  • QC is a set of activities for ensuring quality in products. The activities focus on identifying defects in the actual products produced.
  • QC is a procedure or set of procedures intended to ensure that a manufactured product or performed service adheres to a defined set of quality criteria or meets the requirements of the client or customer.
  • QC involves verification of output conformance to desired quality levels.
  • QC is used to verify the quality of the output
  • QC is a set of activities designed to evaluate a developed work product. It is the process of executing a system with the intent of finding defects.

At its simplest, QC is inspecting, testing or checking something (service or product) to make sure it is as per specification. The intent is to identify anything that is not as per specification, and either fix it or eliminate it, to make sure it conforms to the specifications, and has/does/functions as required.  QC is typically done at the end of the line, before the product ‘goes out of the door’. If the something is not as per specifications then it is called ‘nonconformity’ or a nonconforming service/product.

The objective of QC is to make sure that the products to be delivered are defect free and acceptable as per the quality requirements of the customer. If the products are not found as per the requirements, a suitable corrective action is to be taken.

QC includes all activities that are designed to determine the level of quality of the products for delivery. QC is a reactive means by which quality is gauged and monitored, and includes all operational techniques and activities used to fulfill requirements for quality.

QC does not ensure quality. It only finds instances where quality is missing.  Obviously it is better than nothing, but it has its limitations.