Quality Function Deployment

ABSTRACT

            Quality in the present scenario is a customer determination, not an engineer’s determination or a general management determination. It is based upon the customer’s actual experience with the product or service measured against his or her requirement. Quality just does not happen. It must be built into the product or service being marketed. The present paper deals with the application of Quality Function Deployment (QFD), a tool for listening to customer’s voice for Quality improvement. As a case problem, an attempt is made to apply the technique to major components of centrifugal pump.

INTRODUCTION

        

    Many a times efficiently generated products that are sound from technical point of view fail to achieve acceptance by customers, in such cases defect likely resides in the organization’s perception of its relationships with the market and individual customers.

            This implies that at the time of developing a new product, the relationship among customer’s requirements, design and manufacturing, assembly and inspection, the feed back of quality information must be maintained.

            Quality has become the fundamental strategy for competitiveness today. With the evolution of recent high standard global competitive environment which has experienced rapid changes in economic environment, the field of quality engineering which had been playing vital role since the ancient times, has witnessed the evolution in recent times, in the form of new innovative procedures which are collectively called as TQM. This new revolutionary approach which has started to cause great excitement and furor in the industrial world is poised towards a conversion process which takes the organization from traditional ‘Inspection based quality system ‘ to ‘Prevention based quality system’.

            TQM means not only the quality of product, but also the quality in each and every stage of manufacturing activity. It highly stresses for highest quality at lowest possible cost. TQM involves an organization’s wide effort to a continuous pursuit for quality improvement, quality planning to meet full customer satisfaction. It is a race without a finish line.

            TQM is the application of quantitative methods and human resources to improve material services supplied to an organization, all the process with in the organization, and the degree to which the needs of the customers are met, now and in the future. ‘Total’ in this context means the involvement of every one and everything in the organization in a continuous improvement effort. ‘Quality’ is total customer satisfaction. Total customer satisfaction is the focus of TQM.’Management’ is the leadership of an organization. Management creates and maintains TQM environment.

            Quality Function Deployment (QFD) is excellent tool, for listening to the voice of the customer during initial planning of the product. QFD is a methodology and collection of tools by which customer needs can be back propagated into design and manufacturing.

FOCUS ON CUSTOMERS:

            Only customers can determine total customer satisfaction. In order to know whether the customer is satisfied intense observation is necessary. Only through observation, communication – especially listening and measurement - the organization can determine total customer satisfaction. Quality Function Deployment is excellent for listening to the voice of the customer. Since customers are the main source of income, they are the focus of all total quality management efforts. Without customers the organization ceases to exist. Therefore, every organization and every one in the organization must constantly strive to satisfy the current customers and to create new customers for the future.

DEFINITION OF QFD:

            It is “an overall concept that provides a means of translating customer requirements into the appropriate technical requirements for each stage of product development and production (i.e., marketing strategies, planning, product design and engineering, prototype evaluation, production process development, production, sales).

QFD begins with two principles:

§      Conformance to customers’ valid requirements.

§      Searching out those things attractive to customer that can be used to differentiate            the company’s product from the competitor.

Key elements of QFD:

·                     WHAT----------------------- the output that we seek

·                     HOW--------------------------that which causes the WHAT to happen.

·                     RELATIONSHIP-----------How much each HOW relates to each WHAT

·                     HOW MUCH ---------------The measure of HOW.

Features of QFD:

            QFD is concerned with systematic collection of customers’ likes, dislikes, views, opinions, etc. in either precise or vague forms. Converting these into technical requirements must have to pass through the development of the following:

1.      Planning matrix

2.      Deployment matrix

3.      Process plan and quality control charts

4.      Operating instructions.

The features of the above documents are briefly discussed in the following section.

PLANNING MATRIX:

                It translates the voice of the customer into counterpart control characteristics; i.e. it provides a way of turning general customer requirements drawn from market evaluations; comparisons with competition, and marketing plans into specified final product control characteristics.

DEPLOYMENT MATRIX:

            It translates the output of planning matrix i.e., the final product control characteristics into critical component characteristics. Thus it moves one step farther back in the design and assembly process.

PROCESS PLAN AND QUALITY CONTROL CHARTS:

            These two documents identify critical product and process parameters, as well as control or checkpoints for each of those parameters.

OPERATING INSTRUCTIONS:

            These are based on the critical product and process parameters; these instructions identify operations to be performed by plant personnel to assure that important parameters are achieved.

            Thus QFD envisages the systematic translation of customers needs which are expressed in non-technical terms into technical language at different levels and positions.

Major Steps in Product Improvement Using QFD Approach:

      1.   Market research- collection of customers’ requirements.

a)   Identifying customer needs

b)      Identifying the potential market.

            The information regarding the product requirements in customer terms comes         from a variety of sources:

      i)    Market research data

      ii)   Dealers input

     iii)   Sales department wants

     iv)   Special customer opinion surveys.

2. This is the most critical part of the process and it is usually the most difficult, because it requires obtaining and expressing what the customer truly wants and not what we think he/she expects.
3. Finalizing the customer requirements.
4. Prioritizing the product design requirements.
5. Establishing critical part/process characteristics.
6. Prediction of potential failures and improvements action.
7. Product evaluation at different stages.

CASE PROBLEM:

            As mentioned, QFD is a systematic approach to incorporate the “voice of the customer” into total product cycle involving

·         Product planning

·         Product Design

·         Manufacturing

·         Assembly

·         Service

                                   

                      

QUALITY ASSURANCE:

            This facilitates the identification of system response needed to implement specific actions necessary to prevent defects from being produced or processed any where in the organization .In the present paper an attempt is made to apply the concept of QFD to Centrifugal Pump to develop Planning matrix, Cross-functional matrix, Deployment matrix, Process plan and quality control charts, Work instructions.

            In developing the matrices a likert scale of 1 to 5 is used to establish the relationship between customer expectations and product characteristics. The numerical values assigned indicates the degree of relationship as

0--------------- no relationship

1 --------------- Weak relationship

3 -------------- Medium relationship

5 -------------- Strong relationship

            The vertical section of the planning matrix contains customer expectations like probability, reliability etc., and horizontal axis incorporates alternate design features closely related to the customer needs such as shaft, motor, coupling etc. The varying degrees of correlation between customer needs and a design feature are established by developing a weighted scale of 1-5. The individual needs are ranked for importance and the cumulative effect on each of the design features is obtained.

            Deployment matrix, which identifies critical component characteristics affecting final product characteristics, is developed. Process plan and quality control charts incorporating control point, checkpoint and monitoring method are developed for centrifugal pumps.   

            The cross-functional matrix shows the relationships between individual components of the product and different functions of manufacturing organization. Numerical values assigned indicate the degree of relationship. The individual components of the product are ranked for importance. From the cross functional matrix it is evident that besides design and production, procurement, installation and operation and maintenance play a significant role in meeting the ultimate customer satisfaction. The work instructions are developed for design, production, procurement, inspection and testing department.

PLANNING MATRIX

Customer needs	Ranking	Interactive components
		Impeller	Stuffing box	Motor	Casing	Installation
Less noise smooth operation	5	1	1	3	5	5
Absence of misalignment	5	1	1	3	0	0
Less wear	5	5	1	1	3	0
Less over heating	3	1	1	3	0	0
Good performance	5	5	3	1	3	5
Aesthetic appearance	3	1	0	0	5	0
Reliability	5	1	3	5	0	3

COMPONENT DEPLOYMENT CHART

Component	Finished component characteristics	Critical component characteristics
Shaft	1.      Strength 2.      Stiffness 3.      Straightness 4.      surface finish	1.      outer diameter 2.      length
Impeller	1.      vane angle 2.      number of vanes 3.      internal surface roughness 4.      composition of material	1.      outer diameter 2.      impeller boss diameter 3.      shaft hole diameter 4.      key way dimensions
Casing	1.      internal surface roughness 2.      volute diameter 3.      delivery valve position	1.      suction hole diameter 2.      composition of material 3.      surface finish

CROSS-FUNCTIONAL MATRIX

Components	Ranking	Functions
		Design	Production	Procurement	Installation & operation	Maintenance
Impeller	5	5	3	3	1	1
Casing	3	3	3	3	1	0
Motor	5	3	1	3	5	3
Stuffing box	3	3	3	3	1	5

proCESS PLAN & QUALITY CONTROL CHART

Process	Control Point	Check Point	Monitoring Method
Melting	Temperature	Chemical Composition	X-chart R-chart
Moulding	Mould Shape, Surface roughness	Permeability	X-chart R-chart
Pouring	Temperature	Flowability	By experience
Turning	Outside diameter	Feed, Speed, Depth of cut	Surface gauge, Visual inspection
Finishing	Surface finish	Speed, Depth of cut	Surface gauge, Visual inspection
Key way cutting	Length, Width depth	Speed, Feed, Depth of cut	Surface gauge

WORK INSTRUCTIONS:

1)            DESIGN:

·                     Get details about leakage from the testing center.

·                     If you are informed that leakage is not more than 0.001lit/hr does not attempt any modifications.

·                     If the pump over heats and seizes eliminate rubbing of stationary and rotating parts.

2)         PRODUCTION:

COMPONENT: IMPELLER

·                     Set the job in the 4-jaw chuck of the lathe machine and then check the setting with the help of surface gauge to ensure proper setting.

·                     Do the turning operation up to the required dia and then check the dia with outside calipers.

·                     Do the turning, facing operation and check the width and dia with the help of ring gauge.

·                     Perform the keyway operation.

3)         PROCUREMENT:

·                     Incorporate quality requirements in purchase orders.

·                     Maintain communication and coordination between designers, production engineers to discuss problems and to overcome them.

·                     Adopt 100% inspection for bearings.

CONCLUSION:

            TQM is a journey without destination except for a wish to continuously improve .As customer is the main source of income, he is considered the king of the market and his voice should be given more priority in the development of the product. QFD serves, as a best tool for incorporating customer needs in the design of the product for quality improvement and long term survival of the organization.

REFERENCES:

1.         A.V.Feigenbaum, ‘Total Quality Control’, Tata Mc-Graw Hill, New Delhi.

2.         John Bank “Essence of TQM” Prentice Hall, New Delhi.

3.         H - Lal “Total Quality Management-A practical approach-Wiley Eastern Ltd., New Delhi.

4.         Juran &Gryna-“Quality Planning & Analysis”- Tata Mc-Graw Hill, New Delhi.

5.         T. Amrine & Ritchey - Manufacturing Organization & management-Prentice Hall, New Delhi