qfd rawabdeh paper

Design and Development of a New Quality Function Deployment Software Tool

Ibrahim Rawabdeh1, Lina Momani2 Zain E. Tahboub3

1,3Industrial Engineering Department, University of Jordan, Amman, Jordan 2 Materials & Metallurgical Engineering Department, Balqa’ Applied University, Salt,

Jordan

Abstract

To compete internationally, it is not enough just to build a good product. Today, manufacturers need to create products that satisfy or exceed customers’ needs and expectations. Quality Function Deployment (QFD) is a unique tool that allows a company to plan and design products to meet customers’ needs. QFD is a structured method for product planning. It helps a product project team to represent the customers’ needs and then evaluate how and whether the company can meet these needs. A new QFD software tool was designed and developed. The tool supports the presentation of the data in QFD process through the House of Quality and different QFD matrices. The new QFD software tool is characterized by the easiness to learn and use, has a QFD project focus rather than a single matrix focus, views graphs, presents different data presentation, simplifies data entry to several matrices, and displays statistics about matrix elements. The application of the software has been demonstrated through the development of a new design for a gas burner.

1. INTRODUCTION

To compete internationally, it is not enough just to build a good product. Today, manufacturers need to create products that satisfy customers’ needs. This can be achieved through one important factor in global competition that is quality. The development of techniques, tools and methods that enhance introducing quality in the design process of a new product was numerous. To achieve the objective of introducing quality, Quality Function Deployment (QFD) has been one of the widely used tools.

QFD is a unique tool that allows a company to plan and design products with the customers’ needs. QFD is a structured method for products or service planning. It helps a company to specify the customers’ needs and then evaluate how it can meet these needs. Researchers reported several advantages for using QFD in different applications. Some of the benefits are reducing product development cycle time [1], increasing customer satisfaction [2], providing system approach to design [3] and providing a planning document [4]. On the other hand, QFD suffers from some limitations such as there is no standard QFD tool and it requires great efforts at the early stage [5]. Many QFD practitioners use their own spreadsheets for supporting QFD process implementation, which is an indication of remarkable weaknesses in the available tools. Current QFD software tools misses the ease and quickness of use, does

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not support all QFD tables and matrices. Although available QFD software tools are of high technology, it is not capable of achieving the customer requirement [6]. The objective of this work is to design and develop a new QFD software tool since the available QFD software tools in the market suffer from several weaknesses. The desired software is designed and developed to support the presentation of the data in QFD process through the House of Quality, Part Planning Matrix, Process Planning matrix, and Production Planning Matrix. The capability of the software is illustrated through an example of a new design for a gas heater.

2. REVIEW OF LITERARTURE

Using QFD in topics related to product design exists widely in the literature. Shen et al. [7] demonstrated a new approach to product development using QFD. They showed that the proposed approach would contribute to the creation of attractive product attributes and product innovation. Harding et al. [8] explained how QFD is applied in the concurrent engineering environment. They demonstrated how a Concurrent Engineering environment and QFD technique can be brought together to provide an extended design team with valuable, shared information throughout the design process. Vonderembse and Raghunathan [9] tested the impact of QFD on product development. They concluded that, based on surveying 80 companies in USA, QFD leads to better product designs, lower product costs, and shorter development times. Rahman [10] summarized the quality control methods and techniques developed over the last five decades and categorized them into three broad approaches, each identified with three broadly defined product development stages. He reported that the QFD technique for developing robust designs is becoming increasingly popular in the Western world. Bouchereau and Rowlands [11] and Fung et al. [12] combined QFD with fuzzy logic and artificial neural networks for more customer-oriented and high- quality products. Applying QFD was extended to many other areas where the customers’ requirements need to be stressed and addressed directly. For example QFD is implemented in construction design [13], designing information technology systems [14], educational setting [15], manufacturing strategic planning [16], and software development [6, 17, 18].

Several QFD software tools are available in the market. Two well-known QFD

software tools are QFD/CAPTURE and QFD2000. QFD/CAPTURE has a project focus, rather than a single matrix focus. Users can set up a road map of the lists, matrices, and documents that will be developed for each particular project. The roadmap also links between the matrices. The data that is changed in one matrix will cause related changes in the other linked matrices. QFD2000 provides all the standard matrices as templates. Alternatively, all areas of the chart (including calculations) are fully customized, allowing the user to configure their own chart format. Information in the matrices can be dynamically linked to each other [6]. Herzwurm et al. [6] presented the results of a customer-oriented evaluation of QFD software tools. More than 60 QFD practitioners have been asked about their requirements concerning software supporting the QFD process. The result is a list of 27 customer requirements, which were categorized and summarized to have eleven criteria of assessment, see Table 1. They reported that 27 per cent of the QFD practitioners are still using their own spreadsheets for supporting the QFD technique even though it does not provide the entire QFD fields as any other QFD software which is an indication for remarkable weaknesses of the tools offered in the market. Based on the above review, QFD is used in many applications and expected to be used in more applications. In addition, the weaknesses of the existing

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tools, stresses the need for developing a new-qualified QFD software tool to support the QFD implementation process.

Table 1. Customer requirements Categorized for QFD software Tool [6].

1. Ergonomics: the QFD software tool is easy to use and easy to learn

7. Interpretation: graphical interpretation as well as a “what if when” function are supported

2. Individual adaptability: it is possible to adapt the QFD software tool to fit ones personal needs

8. Utilization of QFD-data: results can be re-used, for example as experience values, and they can be checked for consistency.

3. Work with several users: the QFD software tool is able to administrator several users so that they can all use it simultaneously

9. Integration of other methods: support of methods, such as comparison in pairs, conjoint, analysis, etc.

4. Data exchange with other programs: it is possible to exchange data with other programs, such as Microsoft Excel

10. Support for the introduction of QFD: video and/or multimedia support is available for the training of the participants in QFD project.

5. Administration of QFD-data: the relevant data can be documented and structured, for example in tree-diagram

11. Support by supplier: supplier’s consultation, training, reaction to complaints, etc.

6. Visualization: on screen and printer

3. QUALITY FUNCTION DEPLOYMENT

QFD is a structured approach for clearly specifying the customers’ needs and desires that shape the design of a new product. It translates needs and desires into requirements at each stage of a product design and development. QFD is very powerful for developing or improving new products, and in developing customer-focused systems [4]. It includes identifying and ranking the relative importance of customer requirements; identifying design parameters (or engineering characteristics) that contribute to the customer requirements; estimating the relationships between design parameters and customer requirements and among different design parameters; and setting target values for the design parameters to best satisfy customer requirements [19].

A QFD process (or House of Quality) consists of four phases as can be seen in Figure

1. In each phase a matrix is used to translate customer requirements from initial planning stage through production control in which it represents more specific aspects of the products requirements. Binary relationship between elements of the matrix is evaluated for each phase. Only the most important aspects from each phase are deployed into the next phase [4].

The three key facets to QFD are the cross-functional team charged with implementing

it; the process itself; and the graphical display that guides the process [1]. The fundamental steps of this process are to identify the customer and what the customer wants and how to fulfill what the customers want. In identifying the customer, one must objectively determine the groups that best describe its desired customer base. After the customer base has been identified, the wants of the customer are determined. These wants are commonly referred to as the WHATs, and can be derived by using a wide variety of methods. When the WHATs are established, the QFD team then determines the mechanisms that would satisfy the WHATs. These mechanisms are commonly referred to as the HOWs. The QFD team will decide which ones are selected by using a technical importance rating based on the number of WHATs to which each how contributes. With the WHATs and HOWs in place, the QFD

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team then establishes relationships between them. The team assigns a strength value of none, weak, medium, or strong to each relationship. Furthermore, the team will also assess each HOW with respect to its interaction with the other HOWs to determine if there is positive, negative, or no correlation.

Design Requirements

(HOWs)

Part Requirements

Process Requirements

Production Requirements

Cus

tom

er

Req

uire

men

ts (W

HA

Ts)

Product Planning

Des

ign

requ

irem

ents

(H

OW

s)

Product Design

Par

t Req

uire

men

ts

Process Planning

Pro

cess

R

equi

rem

ents

Production

Planning

Importance Rating

Importance Rating

Importance Rating

Importance Rating

1 2 3 4

Figure 1. The Four Phases of QFD

The QFD team incorporates all this information on a graphical display known as the House of Quality. This house provides a framework that guides the team through the QFD process. It is a matrix that identifies the WHATs, the HOWs, the relationships between them, and criteria for deciding which of the HOWs will provide the greatest customer satisfaction. A more detailed description of the House of Quality is shown in Figure 2. For more details about QFD see Cohen [4].

Correlation Matrix

Hows Objective Target Goals

Whats

Relationship

Matrix

Importance Rating

Customer

Competitive Assessment

Improvement Ratio

Sales Point

Absolute Score

Technical Competitive Assessment

Absolute Scores Relative Scores

Figure 2. Elements of the House of Quality

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4. SOFTWARE DESIGN AND DEVELOPMENT

The objective of this paper is to develop software that combines the desired features of the spreadsheets with the QFD image and elements without getting into ambiguity of the available QFD tools as mentioned in Table 2. One reason is that spreadsheet user had to assess his own application. Satisfying the customer rather than pushing technology should be the aim of the QFD software developers, so providing sophisticated features that are undesirable by the user is a waste of time and can also be a disadvantage since it will add a complexity and ambiguity in using it [6]. Based on a conducted survey, Herzwurm et al. [6] proposed a set of features he called them features of the “perfect” QFD, see Table 2.

Table 2. Design requirements for QFD software Tool [6].

1. Support of Matrix Sequences 11. View as HOQ, tree structure and matrix 2. Divide up a matrix into partial matrices 12. Sorting data according to any criteria you

like considering the hierarchy 3. Data Exchange with ASCII and with spreadsheets

13. Management of versions and variants (scenario definition)

4. Structuring list elements with help of tree and/or affinity diagram

14. Mata plan-Method (group working)

5. Determine calculation (calculation path, free choice of functions, separation of positive and negative values)

15. Support of matrix-view with simultaneous overview

6. Drawing up reports for every element possible (support of standard-text-functions)

16. Adjust appearance of a graphic (axes scales, elements selection, zoom, grid, legend)

7. Overview of the project (Roadmap) 17. Embodying external documents 8. Adjust font type, size and color, zoom factor,

etc. of the screen display. 18. Adjust choices of matrices and matrix- elements as well as adapting outlook

9. Templates for projects or partial results respectively

19. Templates for reports

10. Show/hide matrix elements, list elements, etc.

20. Printing across several pages

4.1 Features of the New-QFD Software

The new QFD software has been designed and developed using Visual Basic (V5) as a programming language to have some of the features of the “perfect” QFD software. The features are:

1. Easy to learn and use because of its simplicity. 2. Has a QFD project focus, rather than a single matrix focus (data that change in one

matrix will cause changes in the other related matrices). 3. Windows Application (WIN95 and above). 4. View graphs. 5. The data is viewed as HOQ, Part Planning matrix. Process Planning matrix, and

Production Planning matrix 6. Display statistics about matrix elements. 7. Printing overall view of the project. 8. Input of data: values can be inserted directly into the HOQ and the other matrices. 9. A tip appears while moving the mouse that guides the user on how to enter the

inputs. 10. Adjust font type, font size, font color, and zoom factor of the screen display.

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The new QFD software consists of the following pages: 1) Welcome page: in which the use enters the general information about

the project, product/service name, objective of the project, and keystone customer. It shows a schematic drawing that illustrates the way the user moves through the software.

2) What Page: It shows the features of File Menu (New, Open, Save, Print, Close, and Exit), Format Menu (Change Colour and Change Font) and Show Menu (Show HOWs and Show WHATs). In this page, the use will enter WHAT, Importance Rating, Value of Competitors, and Sales Point. The user can move among the entered records by using the Forward and Backward buttons.

3) How Page: It shows the features of File Menu (New, Open, Save, Print, Close, and Exit), Format Menu (Change Colour and Change Font) and Show Menu (Show HOWs and Show WHATs). In this page, the use will enter WHAT, Importance Rating, Value of Competitors, and Sales Point. The user can move among the entered records by using the Forward and Backward buttons.

4) HOQ Page: This page organizes the information entered from the previous two pages into the House of Quality matrix. It shows File Menu (New, Open, Save, Print, Close, and Exit), Format Menu (Change Colour, Text, Labels, Background and Font), Calculate Menu (Calculate), View Menu (Graph and legend), Go-To menu (WHATs page, HOWs page, Next Matrix), Comment Menu (comment).

5) Matrix 2: For the second stage of the QFD process, the second matrix defines the design requirements and the part requirements for the product design stage. The same format of the HOQ page is repeated for the second matrix but with the HOWs from HOQ page is already transferred to Matrix 2.

6) Matrix 3: For the third stage of the QFD process, the third matrix defines the part requirements and the process requirement for the process planning stage. The same format of the HOQ page is repeated for the third matrix but with the part requirements from Matrix 2 is already transferred to Matrix 3.

7) Matrix 4: For the fourth stage of the QFD process, the fourth matrix defines the process requirements and production requirements for the production planning stage. The same format of the HOQ page is repeated for the third matrix but with the process requirements from Matrix 3 is already transferred to Matrix 4.

5. SOFTWARE VALIDATION

An example is used to validate the new QFD software. In this example the features of a pencil are redesigned to satisfy customer needs and it was summarized in four matrices [20]. Using the same inputs of the pencil example, Figure 3 shows the results in the matrices that were obtained using the new QFD software. The results are in full match with that of the original source of the example.

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6. CASE STUDY

A case study was conducted to apply the new developed QFD software in designing a new Supper Aladdin Gas Heater (SAGH). There are many complaints from the customers about the inefficient performance of the SAGH. For that, QFD software is used to identify the problem sources and find solutions that satisfy the customers.

To collect the voice of the customers (WHATs), a questionnaire was developed. In the questionnaire, the customers were asked to write their suggestions, opinions and comments about the main SAGH elements, i.e., movement, shape, cleaning, safety, smell and leakage prevention, operation and use, cost, weight, size, heating amount, and durability. To collect the engineering characteristics (HOWs) another questionnaire on how the performance of the SAGH can be improved was conducted and answered by engineers of the manufacturer. The collected data for the WHATs and HOWs are then grouped and organized. The grouped WHATs and HOWs were entered to the HOQ matrix in the QFD software. The correlation matrix, target goals, importance rating and technical competitive assessment and other items in the house of quality were collected during a session that was attended by customers and engineers. It was noticed that several competitors have achieved better customer satisfaction levels in the areas of ease of movement, elegant shape, ease of cleaning, safety tools, and heating amount even though the cost is the same for more than one brand.

Next, the QFD software was used to calculate the scores of the HOQ items. The

results show that the customers required some feature and characteristics that can be added to the current design. The important features and characteristics that were found to be important to the customers are ease of use, smaller size, heat output, elegance, and safety. To achieve the requirements, some modifications and features were suggested as follow. For ease of use, the suggested modifications include use of a movable mesh for ease of cleaning; increase wheels size and use two dimensional wheel movements for ease of movement; use a rotating knob and graphical instructions for ease of ignition; and use soft material (rubber or plastic) for ease of handling. Smaller gas heater size can be achieved through changing the gas jar position and reducing gas heater body size. To produce more heat output, the alternatives were changing the reflecting material, increasing radiation surface distribution area, increase the number of burners, and using two-side heating surfaces. Elegance can be enhanced through adding more decoration, i.e., more curved edges, elegant mesh, attractive colors and stainless steel look. For safety purposes, prevent gas leakage, decrease mesh gap width, reduce the distance between mesh and burners, regulate gas flow rate and adding safety tools (a timer for automatic lock) will help in decreasing the possibility of hazardous accidents.

The important features and characteristics that was found to be important to the

customers and matching the engineering characteristics are increasing wheel diameter for ease of movement (15%), preventing gas leakage (13%), reducing body size (12%), reducing the distance between mish and burner (9%), adding more safety tools (9%), increasing heat output (8%), and controlling gas flow rate (7%). Figure 4 shows the house fo quality for the SAGH. However, Figure 5 shows the gas heater before and after suggested modification.

6. CONCLUSION AND RECOMMENDATION

This study demonstrates the design and development of a new QFD software tool. QFD matrices were constructed using Visual Basic. The features of the software were developed based on some of the requirements of the “perfect” QFD software features. Although the

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study successfully demonstrated how the software is developed, we cannot claim to have found the most effective QFD software. It is recommended to use new features that bring the software to the requirements of the “perfect” QFD software such as sorting data according to any criteria the user like considering the hierarchy, drawing up reports for every elements possible, divide up a matrix into partial matrices and more. It is recommend further development is needed to get benefit from spreadsheets to develop a QFD software that utilize more of the facilities of excel and the QFD project orientation.

REFERENCES

[1] Sullivan, L., “Quality Function Deployment”, Quality Progress, June 1986. [2] Akao, Y., Quality Function Deployment: Integrating Customer Requirements into

Product Design, 1st edition, Productivity Press, Cambridge, 1990. [3] Wasserman, G. S., Gavoor, M., and Adams, R., “Integrated Systems Quality Through

Quality Function Deployment”, Proceeding of the IIE Integrated Systems conference, November 1989.

[4] Cohen, L., Quality Function Deployment: How to Make QFD Work for You, Addison-Wesley, 1st edition, 1997.

[5] Liu, A., Haag, J. L., and Swec D. M., “Quality Function Deployment”, Lewis Research Center, National Aeronautics and Space Administration, November, 1993.

[6] Herzwurm, G., Mellis, W., Schockert, S., and Weinberger, C., “Customer Oriented Evaluation of QFD Software Tools”, Proceedings of the Third International Symposium on Quality Function Deployment, Link Ping, Sweden, October 1997.

[7] Shen, X.X., Tan, K.C., and Xie, M., “An Integrated Approach to Innovative Product Development Using Kano's Model and QFD”, European Journal of Innovation Management; 03:2, pp. 91-99, 2000.

[8] Harding, J.A. Omar, A.R., and Popplewell, K., “Applications of QFD within a Concurrent Engineering Environment”, International Journal of Agile Management Systems; 01:2, pp. 88-98,1999.

[9] Vonderembse, M.A. and Raghunathan, T.S. “Quality Function Deployment's Impact on Product Development”, Int. J. of Quality Science; 02:4, pp. 253-271, 1997.

[10] Rahman, S., “Product Development Stages and Associated Quality Management Approaches”, The TQM Magazine, 07:6, pp. 25-30, 1995.

[11] Bouchereau V., and Rowlands, H., “Methods and Techniques to Help Quality Function Deployment (QFD)”, International Journal of Benchmarking, 07:1, pp. 8-20, 2000.

[12] Fung, R.Y.K., Law, D.S.T., and Ip, W.H. “Design Targets Determination for Inter-Dependent Product Attributes in QFD Using Fuzzy Inference”, Integrated Manufacturing Systems; 10:6, pp. 376-384, 1999.

[13] Abdul-Rahman, H., Kwan, C.L., and Woods, P.C. “Quality Function Deployment in Construction Design: Application in Low-Cost Housing Design”, International Journal of Quality & Reliability Management, 16:6, pp. 591-605, 1999.

[14] Tan, K.C., Xie, M., and Chia, E. “Quality Function Deployment and Its Use in Designing Information Technology Systems”, International Journal of Quality &Reliability Management, 15:6, pp. 634-645, 1998.

[15] Pitman, G., Motwani, J., Kumar, A., and Cheng, C.H. “QFD Application in an Educational Setting: A Pilot Field Study”, International Journal of Quality & Reliability Management, 13:4, pp. 99-108, 1996.

[16] Crowe, T.J., and Cheng, Chao-Chun, “Using Quality Function Deployment in Manufacturing Strategic Planning”, International Journal of Operations & Production Management, 16:4, pp. 35-48, 1996.

[17] Barnett, W.D., and Raja, M.K., “Application of QFD to the Software Development Process”, Int. J. of Quality & Reliability Management, 12:6, pp. 24-42, 1995.

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[18] Aswad, A., “Quality Function Deployment: A System's Approach”, Proceedings of the HE Integrated Systems Conference, November 1989.

[19] Mazur, G. H., “The Application of Quality Function Deployment (QFD) to Design A Course in the Total Quality Management (TQM) at the University of Michigan college of engineering”, International Conference of Quality, Yokohama, 1996.

[20] Shillito, M.L., Advanced QFD: Linking Technology to Market and Company Needs, Wiley-Interscience, 1st edition, 1994.

Whats Page: Input the “Whats” and its related information.

Hows Page: Input the “Hows” and its related information.

House of Quality: Inputs were transferred to the “HOQ” and the correlations are entered

Matrix 2: Parts Planning Matrix (Product Design).

Matrix 3: Process Planning Matrix.

Matrix 4: Production Planning Matrix.

Welcome Page: Input product/service name, customer & objective, and shows a map for the software.

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Figure 4.The House of Quality for Supper Aladdin Gas Heater

Figure 3. Applying the New QFD Software to the pencil example

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Figure 5. Supper ALADDIN Gas Heater a) before and b) after applying the new QFD Software

a) b)

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qfd rawabdeh paper

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