Quality 

                 Inspection, Quality Control, Quality Assurance, and                                      Total Quality Management.

                                     Shri Kanchan Biswas.

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1. QUALITY

The term ‘Quality’ has different perceptions by different people and accordingly, there are many and varied definitions of Quality. In a very broader sense, it can be defined (as per Mil-Q-9858 – “Quality Assurance Engineering”):  

a)     Quality is the totality of features that bears its ability to satisfy a given need.

b)     Quality is conformance to a set of requirements, if met, results in a product fit to use.

The term ‘Quality’ can relate to a product or services rendered to a customer viz. both internal and external customers.

1.1 Inspection, Quality Control & Quality Assurance

Inspection – It is an activity by which Segregation of good and bad products/services can be performed through either tests or measurements or both.

Quality Control – It is all the measures taken to sustain the product or service quality to a specified standard. The QC activities will include control over men, machines, materials, and manufacturing processes.

Quality Assurance - The term, “Quality Assurance” may be defined as a ‘guarantee’ to customers’ satisfaction through controls in design and manufacturing defects. The QA embraces all activities and functions concerned with the attainment of quality. It assures that all the QC measures taken are effective, guarantee quality, and is properly implemented. 

1.2 Quality Control & Quality Assurance

There are two views about the superiority between the QC and QA: 

In North America and Europe, ‘Quality Control’ is the overall system adopted for ensuring quality. ‘Quality Assurance’ as a sub-system (of the overall Quality Control System), provides proof that quality control processes and procedures are in effect being followed properly.

In many other places ‘Quality Assurance’ is regarded as embracing all activities and functions concerned with the attainment of quality, rather than in the narrower sense only of the provision of proof associated with the word “Assurance”. In this case ‘Quality Control’ is regarded as a subsystem of the 'Quality Assurance' system.  In this concept, QC essentially deals with practical techniques adopted for the sustenance of the product quality as set out in the product specification.

1.3 Total Quality Management

Total Quality Management (TQM) is a management approach that seeks to provide long-term success by providing unparalleled customer satisfaction through the constant delivery of quality products and services. To properly execute TQM methods, the entire organization needs to operate as a single unit in the pursuit of excellence.

The seven pillars of TQM are shown below:

1.    Customer Focus -  Give the highest focus on the customer’s experience in all interactions with the organization. From first contact through purchase and continued support, the customer should always be the main priority.

2.      Employee ownership - Involvement of every team member to ensure that complete quality control is important at every level. TQM doesn’t focus on a single department because the goal is to provide customers with a great experience from every level of the organization.

3.     Process-based – Create and implement processes that provide the best products and have the ability to repeat them. Quantifying success and defining the steps taken to get there are essential for the successful implementation of TQM.

4.    System integration - Use every asset available to the company for maximum benefit. This is best achieved through system integrations that combine disparate parts of the organization into a single, well-oiled machine working in complete synergy.

5.     Communication - Ensure every team member is at their best and functions as a value-adding member of that team. Communication and transparency at every level are core tenets of successful TQM practices.

6.    Data-driven – Don’t make guesswork. Instead, use and leverage available data for the improvement of the organization, and decisions are made based on quantifiable facts.

7.     Constant improvement. TQM is not a 'one-time activity'. Reaching 100% perfection is a goal and it must always be pursued to get the organization as close to 100% perfection as possible.   

1.4 Comparison of Quality Assurance Processes

A comparison of the various basic activities performed during Inspection, Quality Control, Quality Assurance, and TQM Processes is shown in table – 1. 

Table – 1: Comparison of Quality Assurance Processes

Inspection	Quality Control	Quality Assurance	Total Quality Management
Error Detection and Rectification	-   Use Statistical Methods -   Follow Quality Standards -   Analyse Process Performance and take action for improvement	-   Consider Quality Systems -   Consider quality costing -   Use Problem-Solving techniques -   Carry out Quality Planning	-   Inculcate Quality culture over the whole Organisation  -   Consider Quality as a strategy for competitive Business -   Provide Staff Empowerment and involvement in Quality Problem Solving & Improvement -   Involve Customers &   Suppliers -   Aim Zero Defect Program

1.5 Growth of Quality Engineering Discipline

In the early part of the industrial growth, the manufacturers (often the artesian) used to be the inspectors for their own products. With the growth of industrial activities, a separate stream of technical branch emerged as ‘Inspectors’, who were assigned the responsibilities of inspecting and segregating the good and bad products. With the increase in the quantity of production, the industry saw a newer scheme of “Statistical Quality Control” procedures. Since 1980 the concept of quality is changed as shown in table - 2. 

Table – 2: Historical Growth of Quality Assurance 

1900s	1940s	1960s	1980s	Post-1990s
Inspection	Statistical Sampling	Organisation Quality Focus	Customer Driven Quality	Quality Management System (QMS)
Old Concept of Quality			New Concept of Quality	International Professional Quality Certification Bodies Monitor the Organisations’ QMS as per International Standards like ISO 9001, AS 9100,   etc.
Inspect for Quality after Production			Build Quality into the process. Identify and correct causes of Quality Problems.
TQC: Total Quality Control; An UK Terminology TQM: Total Quality Management; Used in USA, Japan, and India

1.6 Quality Assurance Manual

Every organization should have a Quality Assurance Manual. The Quality Assurance Manual Should contain the Policies of the organization related to the following issues:

1)     Quality Policy of the Organisation

2)     Management Responsibilities

3)     Quality System being followed

4)     Design Control Procedures

5)     Procedure for Documentation and Data Control

6)     Purchase Procedure and Control

7)     Procedure for Control of Customer-Specified Product

8)     Manufacturing Process Control Procedure

9)     Inspection and Testing Procedure

10)  Procedure for Control of Non-Conformal Product

11)  Procedure for Calibration of Test and Measuring Equipment, Jigs, and Fixtures

12)  Storage, Packing, and Preservation Procedures

13)  Approval of Inspectors, welders, and the record thereon. 

2.  COST OF QUALITY

Quality has dramatic cost implications – dissatisfied customers and consequently loss of business. The company has to pay a very high cost for producing poor-quality goods and services.

2.1  Cost of Quality

Quality has two types of cost elements. These are:

a) Quality Control Cost, and 
b) Quality Failure Cost. 

 

2.1.1 Quality Control Cost

Quality Control Cost is the cost incurred to achieve and maintain high quality. It is like a business investment. It has two elements viz: Prevention cost and Appraisal cost.

a)  Prevention Cost -  all expenditures incurred with the aim of achieving high quality or preventing the occurrence of poor quality.  These include -

  1) Quality Planning Cost – Cost of developing and implementing a quality plan.

  2)  Data collection from customers to prepare customer-desirable specifications.

  3)  Cost of product and process design to meet customer requirements.

  4)  Employee training in quality measurement.

  5)  Cost of maintaining records and data related to quality. 

b)     Appraisal Cost – Appraisal costs are incurred in the process of uncovering the defects. They include all costs incurred to make sure that the Quality standards are met. These include all costs towards the test and inspection during manufacture and failure analysis to get the reason for failure and arrive at the remedial measures. 

       1) They include the cost of quality inspection
                   2) Product testing
                   3) Performance audits
                  4) Cost of equipment used for quality appraisal
                  5) Man-hours spent on measuring quality (QE)

 2.1.2 Quality Failure Cost

Cost consequence of poor quality. These may be loss of ‘Company reputation/Goodwill’ as well as Loss of Business. The quality failure cost may be an external failure cost or an internal failure cost. These are discussed below:  

a)     Internal Failure Cost – Cost associated with poor quality before the product reaches the customers' site. This cost includes:

   1) Rework Cost – Cost for correcting the defective item

   2) Scrap – The defective item is beyond economical repair. (Loss of raw material, labour, machine hour)

   3) Cost of machine time for rejected parts

   4) Salvage action cost.

 b)   External Failure Cost – the cost associated with quality problems that occur at the customers' site. These costs are very damaging particularly because customer faith and loyalty is difficult to regain. Some of these cost elements will be:   

  1) Cost of Quality Inspections
              2) Product Testing
              3)  Performance audit (like welders’ tests etc.)
              4)  Cost of equipment used for quality appraisal
              5)  Workers’ time spent measuring quality.
 

2.2  Discussion on Cost of Quality

Company should invest heavily in prevention and appraisal cost in order to prevent internal and external failure costs. Earlier the defects are found, less costly are to correct. Detecting and correcting cost during product design and production is considerably less expensive than the defects are found at customer site.

External failure cost tend to be particularly high for service sector organisations. This is because with a service the customer spends much time in the service delivery system and there are fewer opportunities to correct defects than there are in manufacturing.

Example of external failure – an airline who has overbooked flights, long delays in airline service and lost luggage. These will have a very long time effect on the passengers.

Various elements of Cost of Quality is shown in figure -1.  A comparison of various Quality Cost elements is shown at figure – 2. 

Figure -1: Elements of Cost of Quality

                                                Figure - 2: Comparison of Cost of Quality

3. QUALITY ASSURANCE FUNCTIONS

The QA functions during various stages of product life cycle is shown below.

3.1. QA During D&D (Design and Development) Stage

1)     Technical Requirement Identification

2)      Verify Technical Specification Document

3)     Technical Specification Reviews

4)     Preliminary Design Document

5)     Preliminary Design Review

6)     Critical Design Document

7)     Critical Design Review

8)     Product Realisation Process.

 3.2  QA During Procurement, Storage & Release for se

1)       Establish acceptance plan as part of the indents/RFQ

2)       Participate in the selection of sub-contractors/vendors.

3)       Establish QA procedures for storage and release of items with associated formats for recording various data towards ensuring trace-ability.

4)   Obtain decisions on non-conformances and regularize them in consultation with regulatory agencies.

5)       Ensure compliance of procedures for proper storage of accepted items in the bonded stores.

6)       Establish infrastructure for servicing and serviceability check

7)     Inspection of storage facilities like cold storage for sealants, perishable/lived item like rubber seals, paints etc. and approve them for proper temp control etc. 

3.3 QA During Fabrication

1)    Approval of the process sheets 

2)    Preparations of inspection plan documents (including inspection instructions)

3)    Qualification of new processes, if any.

4)    Surveillance of following functions of sub-contractors’ QC/QA of the Project team

5)   Evaluations and surveillance of machines, fixtures, tools, installation and workroom, inspections status and their approval etc.

6)    To Ensure Periodic calibration of Jigs, Rigs, gauges etc.

7)    Perform inspection and ensure effective documentation of inspection data.

8)    Obtain decision on non-conformances, if any,

9)    Ensure that proper segregation and identification of defective and downgraded items/ stores.

10)   Carryout analysis of recurring non-conformances and suggest corrective actions

11)   Quality audit originated from compulsory surveillance activities (regulatory functions) in the field of nuclear, space, military and aeronautical industries. These audits were limited to inspection of product and process conformity with reference to safety in view.

 3.3  QA During Assembly

• 1)     The assembly procedures should be documented by the QA team of subcontractor/ vendor.
• 2)   A checklist bringing out the checks / inspection that will be carried out during Assembly will be prepared by the QA team and effective implementation of the same shall be ensured.
• 3)  As part of the assembly document the list of items / parts along with their identification numbers, forming part of the said assembly shall be prepared, along with their inspection/test reports.

3.4 QA During Qualification and Testing & Realisation of Deliverables

3.4.1 Qualification Testing

1)   QA shall approve the Qualification Test Plan and test procedure documents in consultation with concerned RCMA.

2)   The test facilities shall be duly qualified/ validated for use by the QA (work center/ test center) and approved.

3)   QA shall ensure approval of the test rig by DGAQA as per the test rig specification

4)   QA shall participate during qualification tests together with concerned certifying agencies.

5)   QA shall carry out post- test inspection and prepare test report 

6)   QA shall freeze all the documents such as drawings, specifications, process sheets, acceptance procedures, inspection plans, assembly procedures etc. to enable realisation of deliverables without any change.

3.4.1 Qualification Testing

1)   QA shall approve the Qualification Test Plan and test procedure documents in consultation with concerned RCMA.

2)   The test facilities shall be duly qualified/ validated for use by the QA (work center/ test center) and approved.

3)   QA shall ensure approval of the test rig by DGAQA as per the test rig specification

4)   QA shall participate during qualification tests together with concerned certifying agencies.

5)   QA shall carry out post- test inspection and prepare test report 

6)   QA shall freeze all the documents such as drawings, specifications, process sheets, acceptance procedures, inspection plans, assembly procedures etc. to enable realisation of deliverables without any change.

3.4.2       Acceptance Testing

Acceptance Test Plan and test procedure documents shall be scrutinized & be approved by the concerned certifying agencies.

2)     The test facilities shall be duly qualified/ validated for use by the QA.

3)     Failures, if any, should be duly recorded and necessary actions towards failure analysis are to be initiated in consultation with all concerned and corrective actions shall be implemented.

4)     QA shall ensure that each of the deliverables shall be accompanied by the following documents:

a)     History card / Log card /Acceptance tag

b)     Inspection report / Release note

c)     Provisional clearance certificate

d)     Acceptance test reports

e)     User and Maintenance manual

f)      Illustrated part list /catalogue

 3.5 QA During System Integration & Rig Tests

 A sequential integration schedule and procedure shall be evolved by the respective system designers.

1)    QA shall Participate during the integration of the sub-system on the test rig together with IV&V (where S/w are already approved) to ensure proper sequence of integration; perform inspection/checks as identified in the inspection plan document for this activity.

2)       QA shall participate in the testing and ensure implementation of requirements laid down in the relevant test plan.

3)      QA shall approve test rigs.

4)      QA shall participate in test results analysis.

5)    QA shall ensure that the recommendations of Failure Analysis by Defect Investigation team are complied with. 

3.6   QA Function during Failure Reporting & Analysis

1)     In case of failure during testing and service exploitation, the failures shall be appropriately recorded by the quality assurance team. 

2)  A failure analysis committee in the work/test center concerned shall have also the representative of QA team of the work/test center as one of its members. The failure analysis should identify the cause of failure and arrive at a corrective action.

3)     All the corrective action is to be tracked and the implementation of the same shall be ensured by QA.

 

4. QUALITY ASSURANCE FOR VENDOR DEVELOPED ITEMS

4.1 Surveillance and Support to Subcontractors

1)     The QA shall carry out surveillance and provide necessary support to the vendor.  

2)     QA shall maintain vendor record and create mechanism for vendor rating.

3)     QA shall maintain vendor rating.

4)     QA shall provide surveillance and support to the vendor according to his rating.

 

4.2 QA during Hardware Realization at Subcontractor’s Premises

1)     Ensure quality and maintainability aspects as per specifications.

2)     Define clearly the quality implementation mechanism to include,

-        Identification of applicable documents needed

-        Define the acceptance criteria

-        Define surveillance mechanism

-        Define the means to ensure traceability

-        Decisions on waivers, etc.

 

5. QMS AUDIT AND CERTIFICATION

With the advent of Quality Management System of the International Organisations for Standardization (ISO), quality audit has become a requirement for competitive business strategy. Similarly, the International Aerospace Quality Organisation (IAQG) has released requirements for the Aerospace Quality Management Systems (AQMS). Third party audits and certifications followed by annual surveillance audits have been instituted by these international bodies for monitoring and maintaining requisite quality standards by the client organisations.  

      Relevant International Standards:

•        ISO 9001: 2015 – Quality Management System requirement

•        ISO 14001: 2015 – Environmental Management System

•        SAE AS 9100D:2016 – Quality Management Systems – Requirement for Aviation, Space and Defense Organisation.

•        ISO 19011:2018 – Guide lines for Quality and /or Environmental Management system audit.