Quality Function Deployment Developed by Dr A.J. Lowe in collaboration with Prof. K. Ridgway of the University of Sheffield, England This document aims to promote the use of QFD techniques by providing a source of appropriate information and advice to potential and existing users. Quality Function Deployment (QFD) is a set of powerful product development tools that were developed in Japan to transfer the concepts of quality control from the manufacturing process into the new product development process. The main features of QFD are a focus on meeting market needs by using actual customer statements (referred to as the "Voice of the Customer"), its effective application of mutlidisciplinary teamwork and the use of a comprehensive matrix (called the "House of Quality") for documenting information, perceptions and decisions. Some of the benefits of adopting QFD have been documented as : • • • • •
Reduced time to market Reduction in design changes Decreased design and manufacturing costs Improved quality Increased customer satisfaction
Introduction to QFD Yoji Akao is widely regarded as the father of QFD and his work led to its first implementation at the Mitsubishi Heavy Industries Kobe Shipyard in 1972. The interest in QFD in the West was stimulated by reports of the achievements made by Toyota through its application between 1977 and 1984. These included a reduction in product development costs by 61%, a decrease in the development cycle by one third and the virtual elimination of rust related warranty problems (Ref (Ref 1). 1). Yoji Akao defined QFD as "a method for developing a design quality aimed at satisfying the consumer and then translating the consumer's demands into design targets and major quality assurance points to be used throughout the production phase". phase". (Ref (Ref 2) 2) The main features of QFD are its focus on meeting customer needs through the use of their actual statements (termed the "Voice of the Customer"), its facilitation of multidisciplinary team work and the use of a comprehensive matrix for documenting information, perceptions and decisions. This matrix is commonly referred to as the "House of Quality" and is often perceived to represent QFD in its entirety. In addition to the "House of Quality" matrix, QFD utilises "Seven Management and Planning Tools"which are used in many of its procedures: 1. 2. 3. 4. 5. 6. 7.
Affinity diagrams. Relations diagrams. Hierarchy trees. Matrices and tables. Process Decision Program Diagrams (PDPC) The Analytic Hierarchy Process (AHP) Blueprinting
Affinity diagrams This is a powerful method used by a team to organise and gain insight into a set of qualitative information, such as voiced customer requirements. Building an Affinity Diagram involves the recording of each statement onto separate cards which are then sorted into groups with a perceived association. A title card which summarises the data within each group is selected from its members or is created where necessary. A hierarchy of association can be achieved by then sorting these title cards into higher level groups.
Introduction to QFD Yoji Akao is widely regarded as the father of QFD and his work led to its first implementation at the Mitsubishi Heavy Industries Kobe Shipyard in 1972. The interest in QFD in the West was stimulated by reports of the achievements made by Toyota through its application between 1977 and 1984. These included a reduction in product development costs by 61%, a decrease in the development cycle by one third and the virtual elimination of rust related warranty problems (Ref (Ref 1). 1). Yoji Akao defined QFD as "a method for developing a design quality aimed at satisfying the consumer and then translating the consumer's demands into design targets and major quality assurance points to be used throughout the production phase". phase". (Ref (Ref 2) 2) The main features of QFD are its focus on meeting customer needs through the use of their actual statements (termed the "Voice of the Customer"), its facilitation of multidisciplinary team work and the use of a comprehensive matrix for documenting information, perceptions and decisions. This matrix is commonly referred to as the "House of Quality" and is often perceived to represent QFD in its entirety. In addition to the "House of Quality" matrix, QFD utilises "Seven Management and Planning Tools"which are used in many of its procedures: 1. 2. 3. 4. 5. 6. 7.
Affinity diagrams. Relations diagrams. Hierarchy trees. Matrices and tables. Process Decision Program Diagrams (PDPC) The Analytic Hierarchy Process (AHP) Blueprinting
Affinity diagrams This is a powerful method used by a team to organise and gain insight into a set of qualitative information, such as voiced customer requirements. Building an Affinity Diagram involves the recording of each statement onto separate cards which are then sorted into groups with a perceived association. A title card which summarises the data within each group is selected from its members or is created where necessary. A hierarchy of association can be achieved by then sorting these title cards into higher level groups.
Hierarchy trees A Hierarchy tree or Tree Diagram also illustrates the structure of interrelationships between groups of statements, but is built from the top down in an analytical manner. It is usually applied to an existing set of structured information such as that produced by building an Affinity Diagram and is used to account for flaws or incompleteness in the source data. Working down from the top a team can amendments at each level and the completed hierarchy can be drawn as shown below.
Matrices and tables The matrix is a tool which lies at the heart of many QFD methods. By comparing two lists of items using a rectangular grid of cells, it can be used to document a team's perceptions of the interrelationships that exist, in a manner which can be later interpreted by considering the entries in particular cells, rows or columns. In a prioritisation matrix the relative importance of items in a list and the strength of interrelationships are given numerical weightings (shown as numbers or symbols). The overall priority of the items of one list according to their relationships with another list, can then be calculated as shown below.
Tables are also used in QFD to study the implications of gathered or generated items against a specified list of categories. Examples include production planning and analysing customer statements in the Voice of Customer Table shown below.
Relations diagrams Relations diagrams or Interrelationship Di-graphs can be used to discover priorities, root causes of problems and unstated customer requirements. Process Decision Program Diagrams (PDPC) PDPC are used to study potential failures of new processes and services. The Analytic Hierarchy Process (AHP ) AHP uses pairwise comparisons on hierarchically organised elements to produce an accurate set of priorities. Blueprinting Blueprinting is a tool used to illustrate and analyse all the processes involved in providing a service. The House of Quality The "House of Quality" matrix is the most recognised form of QFD (Ref 3). It is utilised by a multidisciplinary team to translate a set of customer
requirements, drawing upon market research and benchmarking data, into an appropriate number of prioritised engineering targets to be met by a new product design. There are many slightly different forms of this matrix and this ability to be adapted to the requirements of a particular problem or group of users forms one of its major strengths. The general format of the "House of Quality" is made up of six major components which are completed in the course of a QFD project: 1. Customer requirements (HOW s) - a structured list of requirements derived from customer statements. 2. Technical requirements (WH ATs) - a structured set of relevant and measurable product characteristics. 3. Planning matrix - illustrates customer perceptions observed in market surveys. Includes relative importance of customer requirements, company and competitor performance in meeting these requirements. 4. Interrelationship matrix - illustrates the QFD team's perceptions of interrelationships between technical and customer requirements. An appropriate scale is applied, illustrated using symbols or figures. Filling this portion of the matrix involves discussions and consensus building within the team and can be time consuming. Concentrating on key relationships and minimising the numbers of requirements are useful techniques to reduce the demands on resources. 5. Technical correlation (Roof) matrix - used to identify where technical requirements support or impede each other in the product design. Can highlight innovation opportunities. 6. Technical priorities, benchmarks and targets - used to record the priorities assigned to technical requirements by the matrix, measures of technical performance achieved by competitive products and the degree of difficulty involved in developing each requirement. The final output of the matrix is a set of target values for each technical requirement to be met by the new design, which are linked back to the demands of the customer.
Models for Applying QFD Tools The "House of Quality" can be used as a stand alone tool to generate answers to a particular development problem. Alternatively it can be applied within a more complex system in which a series of tools are used. The "Clausing Four-Phase Model" is the most widely known and utilised of these approaches (Ref 3). It translates customer requirements through several stages into production equipment settings; using three coupled QFD matrices and a table for planning production requirements (as shown below).
The less known and more comprehensive "Matrix of Matrices" model provides developers with thirty matrix tools and tables (Ref 4) which consider development steps not included in the "Four-Phase" approach (see below). This represents the full QFD tool kit and practitioners should select and adapt from this set as appropriate rather than attempt to implement it in its entirety.
Such is the flexibility of the matrix tools utilised by QFD, its methods have now been applied in many fields other than product development. One of the main areas is in strategy formulation and implementation. As with other Japanese management techniques some problems have been encountered when applying QFD within the western business environment. These are mentioned on the practitioner’s tips page and are also addressed from a US perspective by Bob Hales.
The Implications of Arrow's I mpossibility Theorem on QFD The Impossibility Theorem Hazelrigg (Ref 12) has argued that design approaches such as QFD, that seek to optimize the value of a design to its customers can lead to highly erroneous results. He bases this argument on the impossibility theorem first presented by Kenneth Arrow (Ref 13). Kenneth Arrow considered the problem of constructing a utility function to express the preferences of a group and showed that apart from in some very special cases, utilities cannot be used. To demonstrate his theorem the concepts of optimisation and utility must be understood. Optimisation Optimisation is performed only with reference to some specific measure of value. In the example below the optimisation of "y" can be achieved by the appropriate selection of "x". y = f (x) (Value function for "y") If the value function "f (x)" cannot be expressed, the optimisation cannot be accomplished. The purpose of optimisation methodology is to find the set of values of "x" that obtain the maximum value of "y", even when it is necessary to search across an infinity of possible values of "x". Utility Utility is an economic value of preference and has the unit of utiles. For example an individual's preference for three alternatives A, B and C; where A is preferred to B and B is preferred to C, can be expressed as : A>B>C In this case each option can be assigned a number of utiles, as a measure of the utility of each preference. The above could then be expressed as a utility function as shown : uA >uB > uC The impossibility theorem considers the preferences of a group of three rational individuals which are shown in the table below : Individual
Preferences
A vs. B B vs. C A vs. C
I
A>B>C, A>C A
B
II
B>C>A, B>A B
B
C
III
C>A>B, C>B A
C
C
Group preferences
A>B
B>C
A
C>A
While each individual has a rational set of preferences it is obvious that combining these to form a group utility function presents a problem. Optimisation for the group using this data is impossible. Hazelrigg (Ref 12) argues that this situation is not a rare case but is in fact the norm and as the preferences of individuals within a group are defined in greater detail, the higher the chance of encountering this type of problem. The Impossibility Theorem Hazelrigg (Ref 12) illustrates the potential consequences of the impossibility theorem with a simple example that shows how combined preference data can lead to the design of a product that satisfies none of the customers : A simple product possesses three attributes: colour, size and shape. Each of these can be one of two options; colour can be Red or Green, size can be Large or Small, shape can be Bumpy or Flat. There are three rational customers whose preferences for each of the attribute options are described in the table below. In this case values of "Attribute Utility" are used (where 1.0 is the maximum utility and 0.0 represents the lowest utility where the customer will not want the product at any price), these are multiplied together in order to measure the overall utility a customer has for a particular product configuration. (e.g. customer I has a utility of 1.0 × 0.9 × 1.0 = 0.9 for a Red - Small - Flat product).
An optimisation approach based upon such preference findings would result in a design that was Red - Large - Bumpy; as on average for the group Red is preferred to Green (customers I and II preferring Red, while only customer III prefers Green), Large is preferred to Small and Bumpy is preferred to Flat. But this combination has a utility of 0.0 for all three customers (e.g. for customer I the overall utility for Red - Large - Bumpy = 1.0 × 1.0 × 0.0 = 0.0) and so is the worst possible design. Based on these examples Hazelrigg (Ref 12) argues that the use of averaged group preference data is
inappropriate in the optimisation of product design. Consequences for QFD P ractitioners The above example is not entirely representative of the manner in which customer requirement data is defined and combined in QFD. Despite this the issues that the theorem raises still need to be considered, as any form of averaging of individual responses will not necessarily optimally represent group requirements. In the example a strategy for the manufacturer's success is to supply a range of products in each colour, size and shape combination to satisfy the three customer types simultaneously. This case though is simplistic and in genuine engineering design situations the number of attributes, customers and sets of preferences are very much greater. The occurences of such irrationalities in complex grouped preference data would be considerably less obvious. Considering the many documented examples of QFD application, this problem does not appear to be occuring on the magnitude that would be predicted by Hazelrigg's (Ref 12) arguement. It could therefore be concluded that in real, complex products these problems only manifest themselves to a small extent, lowering the optimality of the overall design, but not rendering it entirely inappropriate as may be anticipated. Alternatively the focus of QFD designers upon specific market segments may minimise the occurence of incompatible preference groups. Accurate segmentation of the market through the use of tools such as the Voice of the Customer Table could be used to minimise the consequences of these problems.
Developing New P roduct Concepts from Core Competencies This case study was undertaken within a medium-sized supplier to the construction industry. The aim of this project was to apply QFD tools to generate a range of new product concepts that were appropriate to the company's skills and technology base. To ensure the suitability of these concepts the first part of the project focused upon identifying the company's current core competencies (Ref 14) and its market sectors, in a programme of internal interviews. These were entered into a "creativity matrix" which was used to focus a team brainstorming exercise. The resulting concepts were developed to a limited extent before being evaluated using a House of Quality type matrix. During the interview stage the types of customers served by the company were identified :
Architects - design the building or structure (Architect requirements include meeting their client's needs and expressing their building concept with minimal technical limitations •
Structural Engineers - engineer the design of the building (Engineer's requirements include ease of design, specification and calculations to achieve the technical demands made by the architect.) •
Contractors - build the structure and purchase the materials from the company (Contractor requirements include; lowest cost to maximize margins, meeting project schedules, safety on site, ease of storage, handling and assembly.) •
Building Users - (users requirements include portraying the right image/atmosphere, ease of maintenance, inspection, access, minimal running costs etc...) •
Public - live and work around the building (The public's requirements include the structure's impact upon the local environment and the image presented of the city/region/country.) •
Also the interviews gathered a list of statements on company capabilities (as defined by Ref 15) which were compiled in response to questions regarding the competitive advantages of the organisation. The first exercise of a study group of three key personnel from the company, was to sort these capabilities and so highlight the areas of its current competency in an affinity diagram (shown below).
Four core competencies that form the root of the company's competitive advantage were identified : Product Guarantee - a unique in the industry guarantee of product performance and a reputation for having zero in-service failures. •
Steel Expertise - internal skills in the application of high strength steels in addition to a partnership with a major steel manufacturer. •
Market Presence - a strong brand name, a good reputation in the construction industry and many contacts among architects and engineering consultancies. •
Customer Service - technical advice, site services and languages for foreign customers. •
The second task of the study group was to apply the "creativity matrix" (a basic two-dimensional matrix) in a brainstorming exercise to generate new product concepts. This tool was utilised to focus the discussion's of the group on the interrelationships between the four competencies and the company's five major market segments. Each matrix cell was used to record the degree to which the competence was important in meeting the needs of the market segment, highlighting weaknesses in the current product range and stimulating creative discussions on the potential for new products. The completed creativity matrix is shown below.
The main observation drawn from this matrix was the weakness in the provision of customer service in many of the market segments. Additionally the strong market presence was not developed across all the markets. As the scope for further improvement in product performance through the application of more advanced steels, was limited; it was emphasised that developing material properties such as corrosion resistance could be an
opportunity for maintaining technical superiority. The discussions stimulated by the matrix led to eight new product concept themes. The process of developing these concepts (which involved extensive discussions with internal and external expertise) resulted in five being submitted to a final evaluation stage. The last task for the study group was to apply a simplified House of Quality matrix to the evaluation of the remaining concepts against the business objectives of the organisation (as shown below).
Case Study Conclusi ons The application of Affinity Diagrams proved to be a powerful method for identifying the core competencies of an organisation from a qualitative internal survey. The compatibility of these techniques with the concepts of capabilities (Ref 15) and competencies were identified as being particularly valuable in this context. The formation of a multifunctional team and allocating the time of the selected key personnel for their involvement in this study, proved difficult within this resource restricted organisation. In this case using a team of three for two relatively short meetings, meant that these demands were minimised and the tasks were successfully completed. The use of a small team did incur drawbacks in the limited range of perceptions available in the discussions and meant that priorities were not always assigned from a holistic perspective. Also important was the input of a strong chairperson in these meetings to avoid the team's tendency to become embroiled in lengthy discussions regarding each and every matrix cell. The experience gained as a result of this study has been incorporated in the practical advice provided for QFD users.
Strategy Formulation w ithin an SME The objective of this case study was to develop a tool which could challenge strategic beliefs and stimulate innovative strategic thinking within a traditional manufacturing SME, based upon understanding the requirements and perceptions of its customers. An adapted form of the "House of Quality" matrix was devised for this application (illustrated below).
This case study was carried out in a supplier of the UK coal mining industry. The company was small with less than thirty employees and utilised low technology processes to produce a standard product range. The project was initiated with an internal audit of the company carried out using a series of interviews with its key personnel. These interviews focused upon the business objectives of the company, elements of its current strategy for achieving these objectives and its main cultural characteristics. As the objectives and strategy of the company were not explicitly formalised, the personnel responded to these questions with a variety of responses. In many cases the questions had to be re-phrased more directly (e.g. how does your company succeed in winning orders?) to gain insights into its strategic elements. The statements were grouped in the affinity diagrams illustrated below :
The second stage of the project involved gathering data from the company's customers. Following an interview with one customer a questionnaire was devised that focused eight key requirements and avoided commercially sensitive questions asking directly about the performance of competitive companies. Upon the completion of the external and internal surveys, two matrix building meetings were carried out involving the Managing Director, a company sales representative and the Teaching Company Associate operating in the firm. The first of these meetings focused on the feedback of the information gathered in the two surveys, and the interpretation of this data through building the affinity diagrams shown above. In the second meeting the strategy formulation matrix illustrated below was constructed. The discussions surrounding the allocation of weightings in this matrix generated a list of conclusions regarding the strategy taken by the company at that time.
Conclusions drawn from the completed matrix tool : Overall the company's strategy appeared suited to the needs of its customers. This was due to the active role the company management and sales representative play in communicating with customers and providing services to meet their needs. The company's performance as perceived by its customers highlighted that it had no distinctive advantage over its competitors. The strategic elements of aggressively undercutting competitor's prices and minimising overheads were perceived to have a negative influence on the company's performance in meeting the quality and the flexibility requirements of customers. There is an absence of strategic elements that relate to meeting the quality and safety requirements of its customers. Despite the company's expressed focus on meeting customers' exact needs in terms of products and deliveries, the flexibility performance of the company was the lowest rated relative to its competitors. Strong customer relations were expressed as a key component of the company's competitive strategy, but these relations were rated the lowest in importance by customers. The Descriptors Correlations matrix highlighted a synergy between the pursuit of customer relations and the flexible pursuit of the opportunities that arose through these relations. It also indicated a negative influence of the focus on minimal overheads upon the flexibility element of its strategy. •
•
•
•
•
•
•
The Requirements Correlations matrix indicated that the majority of customer requirements were positively related. Where negative relationships were identified, these indicated the compromises necessary in the company's manufacturing system in order to meet these conflicting requirements. •
Recommendations made to company management included : Maintain the emphasis on an aggressive pricing policy. Review emphasis on customer relations. Freed managerial time should be devoted to company development. Institute low cost systems and procedures to develop company flexibility (e.g. set-up reduction...) Initiate a pro-active approach to the market, as opposed to imitating the moves of competitors. Aim to develop an innovative service appropriate to the company's capabilities (e.g. a guaranteed two day delivery time). Implement low cost techniques to pursue a strategy with greater focus on quality and safety issues. (SPC, increased responsibility and autonomy, quality circles and removal of piecework pay incentives). • •
•
•
•
Although the case study was not completed as initially envisaged the company benefited from the issues that were raised and a number of lessons were learned which influenced the success of later QFD case studies. These lessons are included in practical advice.
Evaluating I nnovative P rocessing Technologies The largest barrier to the implementation of many innovative materials processing technologies is in meeting financial hurdles. The perceived risks involved due to the required high expenditures and the difficulty in predicting future cash flows commonly result in a pessimistic, wait-and-see approach amongst potential manufacturing users. This policy incurs the risk that competitors with greater foresight could steal technological leadership and gain a significant competitive advantage which will be costly and time consuming to recover. For thixoforming, a form of semi-solid alloy processing, (Ref 16) this policy has hindered the adoption of the technology in the UK. While manufacturers in Italy, the U.S., Switzerland and Germany have successfully commercialised the technology; manufacturing such products as automotive fuel rails, suspension and steering components; UK manufacturers are still debating the financial implications of implementing the process. The Thixoforming Research Group based at the University of Sheffield identified this obstacle and initiated a project to develop a cost benefit appraisal computer package (Thixocost) for use by potential UK users of the technology, to facilitate their accurate evaluation of the full financial implications of implementing the process. It was recognised during the
development of this package that comprehensively quantifying all the "intangible" benefits and drawbacks associated with the process, necessitates the commitment of significant time and resources by any manager wishing to undertake this evaluation. What was desirable was a tool to perform a relatively rapid check on a proposed product's suitability for thixoforming before this laborious cost data gathering process was initiated. As a result an element of the software development became the application of a QFD "prioritisation" type matrix to the evaluation of a potential product's characteristics. This was used to relate a generic set of product descriptors against the defining characteristics of the technology. Advantages and Draw backs of Thixoforming The processing of metal alloys heated into a semi-solid state has several advantages over conventional forming processes : It is an energy efficient process which is easily automated and controlled to achieve consistency. Production rates are similar to pressure die casting or better due to more rapid solidification. Smooth filling of the die with no air entrapment can be achieved, plus low shrinkage porosity gives parts of high integrity. Lower processing temperatures reduce the thermal shock of dies, promoting die life and allowing the processing of high melting point alloys (such as tool steels and stellites) that are difficult to form by other means. Fine, uniform microstructures give enhanced component properties. Optimised component design can be used to improve yield from raw materials and give component weight savings. Reduced solidification shrinkage allows more complex parts to be produced to higher tolerances reducing additional processing operations of many components. •
•
•
•
• •
•
The extent to which these benefits can be achieved is dependent upon the design of the component and its dies, the optimisation of processing conditions, the degree of the technology's integration into the existing production process and the demands of an organisation's business environment. There are also a number of drawbacks which limit the current commercial viability of thixoforming : The raw materials on which the process depends are more expensive than standard alloys and have only a small number of suppliers. Considerable research effort and expenditure is required to develop and implement a viable manufacturing process, due to the currently limited available process knowledge. Die development costs are higher than for conventional forming technologies where recognised design practices can be applied. •
•
•
The personnel required to develop and operate thixoforming equipment within an organisation require a higher level of training than equivalent traditional operators and will be more expensive to employ. •
These characteristic advantages and drawbacks were grouped into a set of nine process descriptors by the members of the Thixoforming Research Group, to be utilised in the technology evaluation tool. Based upon this set a list of relevant product characteristics were identified and similarly grouped to give eight product descriptors. These two lists were entered into the evaluation tool as shown below.
Evaluating Matrix R elationships As a generic tool was desired, each product characteristic was allocated three settings (e.g. Critical / Important / Unimportant and High / Small / No etc..). For each of these settings, values had to be entered into the cells of the appropriate matrix row. First each of the various product characteristic settings were defined as shown in the table below : Product Setting 1 Characteristic
Setting 2
Setting 3
Weight
Critical : Minimising the weight of the component is a critical issue
Important : The weight of the component is important but not critical
Unimportant : The weight of the component is not important
Strength
Critical : The strength of the component is a critical issue
Important : The strength of the component is important but not
Unimportant : The strength of the component is not an important issue
critical
Geometry
Complex : The geometry of the component is highly complex. e.g. fuel rail
Medium : The geometry of a component is of medium complexity
Simple : The geometry of the component is basic. e.g. a chisel
Tolerances
Critical : The meeting of demanding material property and dimensional tolerances is a critical issue
Important : Material property and dimensional tolerances are important but not critical
Unimportant : Meeting dimensional and material property tolerances is not important
Price Premium
High : The market will allow a premium price to be charged for a thixoformed product
Medium : The market will allow a small premium price to be charged for a thixoformed product
No : The market will allow no premium to be charged for a thixoformed product
Lead Time
Long : The lead time between receiving an order and despatching a product is not important and is greater than 3 months
Medium : The lead time between receiving an order and despatching a product is between 3 months and 1 month
Short : The lead time between receiving an order and despatching a product is critical and is less than 1 month
Flexibility
High : A customised product is produced in small batches, unique to each customer
Medium : A medium sized range of standard products is produced
Low : A single standard product is produced in large batches
High : In the current process there are more than 3 machining / finishing / reinforcing operations which could be removed through thixoforming
Medium : There are 1 or 2 machining / finishing / reinforcing operations in the current process which could be removed through thixoforming
No : There are no existing process steps which could be removed through thixoforming
Finishing Operations
Based upon these understood definitions, members of the Thixoforming Research Group identified the technical issues relating to each matrix row and used these to specify a set of weightings values. The resulting tool was
incorporated into the software written in Visual Basic 4.0, in a manner which automated a user's interface with the technology evaluation tool. Setting Technolog y Viability Scores The completed tool was initially applied to the characteristics of a range of commercially produced thixoformed products, to establish the range of scores anticipated for these types of product. Next the characteristics of several products recognised as unsuitable for thixoforming where entered into the tool, to ensure the viability scores were significantly differentiated from those verified as commercially feasible. The outcome of these tests were used to set the matrix interpretation scores at appropriate levels (shown in the table below), and these scores were incorporated into the software to provide a user with an immediate recommendation on any entered set of product characteristics. Product Evaluation Score
Software Interpretation
The product under consideration is suitable for the application Greater than of thixoforming technology and a detailed cost benefit analysis 100 should now be undertaken. The score allocated to this product by the Multi-Attribute Matrix Analysis shows it to be a borderline case. You may wish to Between 100 repeat this evaluation paying close attention to the and 80 characteristic settings and importance weightings chosen before deciding whether to pursue a further cost benefit analysis. Less than 80
The product under consideration is presently unsuited to the application of thixoforming.
Conclusions The final version of the thixoforming evaluation matrix (shown below) is available with the ThixoCost cost benefit appraisal software and its effectiveness has been verified by its use by several current and potential users of thixoforming in both the U.S. and the UK. The application of this slightly adapted Prioritisation Matrix has successfully encapsulated the expertise of the Thixoforming Research Group, in a tool which can be rapidly utilised by any manager considering the implementation of thixoforming.
It should be recognised that this technology evaluation tool does not substitute for a comprehensive economic analysis. The level of subjectivity necessary in allocating generic characteristic settings, importance weightings and interrelationship scores, means specific accuracy cannot be achieved in each case. Instead the value of this tool is in the focusing of a subsequent economic analysis (on the process issues highlighted by the highest total column scores in the matrix), or by removing the need for such an analysis altogether. This approach could as effectively be applied to the analysis of other innovative technology applications and the author would be particularly interested to hear of or become involved in any such activities.
Tips for QFD P ractitioners The following advice is based upon the experienced gained in QFD case studies carried out by Research Group at the University of Sheffield and also draws on the work of Bob Hales (Ref 7) who has suggested adaptations to QFD techniques to make it more compatible with U.S. business culture. This advice is important in overcoming three types of drawback commonly encountered in QFD applications which are detailed in the table below. Type of Problem
Implications
Misinterpretation
Misunderstanding the correct QFD techniques e.g. mixing technical measures with customer requirements, use of unsorted data and interpreting the "FourPhase Model" as serial product development.
T im e a n d r e s o u r c e
QFD can demand significant initial
constraints
investment in training, project facilitation and market research. Its use of a team of key functional representatives makes high demands on stretched personnel resources. Building large, complex charts can make a QFD project very time consuming. In some cases personnel have been unwilling to repeat the use of QFD due to the high demands of the process.
Culture clash
QFD is based upon Japanese management practices, and so the characteristics of Western management can limit the effectiveness of its techniques. Symptoms of this conflict include poor internal communications particularly between functions, problems building consensus in the QFD team and low team or management commitment to the process.
The widespread application of QFD in the U.S. and the achievements of these projects illustrate that the techniques are a valuable resource for Western organisations. The potential benefits for UK users are significant, but they need to adopt a flexible approach to both adapting and applying QFD tools. The key to successful QFD implementation in the UK is to account for the characteristics of our organisations and attempt to minimise the obstacles to initial applications. The Table below offers a list of practical advice for embarking upon a programme of QFD application : Limit demands on company resources
The use of a small QFD team reduces the threat to business cultures where formal teamwork is unknown and will facilitate discussions and achieving consensus. Efforts should also be made to limit the number and length of meetings. Alternatively an individual can build QFD matrices using information gathered in separate interviews. In this case care must be taken in ensuring similar definitions are understood by all participants, and in interpreting and combining the data in
the matrix. Selection of team members
The choice of QFD team members is fundamental to a project's success. The selection should include the most positive personnel with the closest links with customers. The correct choice will facilitate open discussions, the resolution of conflicts and encourage team commitment to the project.
Recognition of senior management
The involvement of senior management in the formulation of a QFD project is important in gaining their commitment to the process and in providing incentives for personnel participation.
Intuitive checks
The results at each stage of a QFD project should be compared with the intuitive views of the team members. Where a divergence is noted analysis can be directed at identifying the factors responsible. The appropriate changes can then be made to the matrices or the perceptions of the team.
A flexible approach
Care must be taken to adapt the approach used to apply the QFD project to the circumstances of the organisation. e.g. realistic objectives chosen, format of team and meetings, type and complexity of tools used.
Limit the functional or hierarchical conflicts in the QFD team
For an initial QFD implementation functional or hierarchical barriers within the team should be limited to minimise disruptive conflicts. As experience is gained and the techniques are accepted then more sensitive barriers can be challenged.
Conflict avoidance The selection of team members can reduce the negative aspects of conflict in discussions. Another approach is for the team to list all the issues relating to a contentious matrix relationship and assign weightings to each of these before producing an overall weighting. This divides a difficult discussion into logical steps and helps to separate the individuals from the issues being considered. Use small matrices
Limiting the size of matrices to eight by eight key requirements helps avoid complexity, focuses the team on the most important issues and reduces the pressure on resources.
Use sensitive
Be aware of the commercial sensitivity of the
market surveys
information demanded in a standard QFD project. For instance customers may not be willing to report on the performance of competitive products and will have a low opinion of a company demanding such information.
Document issues raised
Record the issues raised during discussions on each matrix interrelationship so at a later date the weighting can be justified drawing upon the original reasoning.
Identify key relationships
When completing the interrelationship matrix, initially highlight the key relationships which have the greatest impact on customer satisfaction. Then focus discussions on establishing the issues relevant to these, rather than a time consuming consideration of every matrix cell.
Recognition of participants
Appropriate incentives must be used to encourage participation. The team should be credited with the achievements of the project on individual and group levels.
The main lesson for would-be QFD Practitioners is to take a realistic approach and develop their own unique QFD system which is appropriate to the characteristics of their own organisation and cultural background, rather than attempt to rigorously apply QFD as described in text books. For more details please refer to the forthcoming article in the Engineering Management Journal.
The Voice of the Customer Table The Voice of the Customer Table (VOCT) is a component of the "Comprehensive QFD" (Ref 6) system (itself a subset of the Matrix of Matrices) and its use is a valuable preliminary exercise before building a "House of Quality" matrix. It has two parts. The purpose of the VOCT Part 1 is to : 1. Identify customer usage of the product or service. 2. Predict possible usage of the product or service. 3. Assist in market studies through usage analysis.
The VOCT Part 1 is completed for each customer statement, for which a
customer I.D., a customer demographic (sex, age, location etc...) and product use information are recorded. The product use questions are categorised into Who, What, When, Where, Why and How (e.g. : Who uses it? Who will use it?; What is it used for? What could be the use?...) which when analysed in conjunction with the demographic information serve to highlight different market segments into which customers may be divided. The two columns under each "Use" category differentiate entries that are gathered directly from customers from those that are generated internally within the company. The VOCT Part 2 identifies demands that are spoken and unspoken based upon the Voice of the Customer and usage information. These are transformed into useful reworded statements for use in the QFD process (e.g. a customer requirement entry in a "House of Quality" matrix). For each statement the table requires : 1. Demanded Quality (Customer Requirements) items are developed in terms of the organisation. 2. Measurable Quality Characteristics (Technical Requirements) that ensure Demanded Quality items will be met, are identified. 3. The Functions that are necessary for the product to be acceptable to the customer are identified. 4. The Reliability of the product in satisfying its intended Function for a specified time period is considered. 5. Comments can be added to raise other important factors
The outputs of the VOCT can then be entered into a “House of Quality" matrix to begin the product planning process. The application of the VOCT for identifying segments in a customer group is
particularly important in avoiding the problems highlighted by the Impossibility Theorem.
QFD in Strategic Decision-Making The flexibility of the matrix tools utilised by QFD has enabled many applications to issues other than product development (these are often referred to as non-conventional QFD applications). These applications have included performance evaluation, supplier certification, health care to name a few examples. In 1988 Sullivan was first to describe the use of QFD in strategy formulation and implementation in the West (the figure below illustrates his policy deployment matrix). This facet of QFD application has since developed into a significant field with now more than twenty different applications and many beneficiaries documented.
This page currently offers a brief review of the majority of these applications (see tables below), and hopes in the future to describe the important developments in this field. The table below documents authors who have described QFD strategic applications utilising a single matrix: Authors
Description of application
Maddux, Amos & Wyskida
Used QFD to facilitate strategic planning decisions at the Production Engineering Division of the U.S. Army Missile Command.
(1991) Philips, Sander & Govers (1994)
Describe a QFD procedure to formulate annual policy and demonstrate their approach by comparing it to policy formulation at Philips EBEI-IC in Taiwan.
Hummel (1996)
Detail the use of QFD by a consulting organisation for strategic planning and describe the application of a five-step approach within the University of Vermont to build a single HOQ type matrix.
Ferrell & Ferrell Jr. (1994)
Describe the use of a single QFD matrix applied to business planning within a small U.S. appraisal firm to translate customer requirements into targets for relevant controllable business parameters.
Describe the application of QFD to strategic product planning in which a matrix is used to set strategic goals, prioritise Cohen (1995) product family members, highlight products that fail to meet market needs and those needs which currently are not satisfied. Guinta & Praizler (1993)
Detail three case studies of strategic applications of QFD, identifying key new customers, highlighting the most important requests for quotation and the design of an employee training programme.
Prasad (1995)
Highlights the problems of incompatible tactics in the application of Just-in-Time techniques and advocates the use of a JIT quality matrix developed from the HOQ.
Lu, Madu, Kuei & Winokur (1994)
Describe a method to integrate the techniques of the Analytical Hierarchy Process (see Saaty, 1990 for a description of AHP), QFD and benchmarking in a single matrix tool to analyse strategic marketing policy.
Multiple matrix strategic QFD applications: Authors
Description of application
Describe McDonnell Douglas Technologies Inc. use of a threeAtkins & phase QFD matrix approach within an "Integrated Strategic Crisafi (1995) Planning Process".
Lu & Kuei (1995)
Explore the application of a four-phase QFD procedure to strategic marketing planning. Gathered customer requirements are used in a series of matrices to generate long term corporate goals, marketing-related objectives, marketing strategies and finally marketing tactics.
Day (1991)
Describes the application of QFD matrices to business planning using a four-phase approach, which converts company vision into individual responsibilities and action plans.
Chen & Bullington (1993)
Describe the use of QFD in developing a strategic planning process for the research activities of an academic department at Mississippi State University. They utilised a four-phase approach and used the needs of appropriate funding agencies to drive the process.
Lowe & Ridgway (1998)
Applied a two-phase approach based upon QFD techniques for the identification and interpretation of an organisation's core competencies.
Barnard (1992)
Describes a strategic planning approach that involves nine steps to develop a series of five appropriate HOQ type matrices.
Lyman, Buesinger & Keating (1994)
Describe the application of six QFD matrices as a decisionmaking tool for focusing product development efforts within Chevron Chemical Co.'s Specialty Polymers Strategic Business Unit.
Hales (1995) & (1997)
Describes two QFD based approaches to strategic decisionmaking and project selection used by a consulting agency.
Strategic QFD Referen ces (in order of appearance) Sullivan, L. P. (1988) , "Policy management through quality function deployment", Quality Progress, Vol. 21, Part 6, pp. 18-20. Maddu x, G. A., R. W . Amos and A . R. W yskida ( 1991) , "Organisations can apply quality function deployment as strategic planning tool", Industrial Engineering, September, pp. 33-37. Ph ilips, M., P . Sander an d C. Govers (199 4) , "Policy formulation by use of QFD techniques: a case study", International Journal of Quality and Reliability Management, Vol. 11, Issue 5, pp. 461-50. Humm el, K. (1996) , "Abstracting the QFD: Applying the power of QFD to strategic planning", Transactions from the Eighth Symposium on Quality Function Deployment, Novi, Michigan, pp. 93-108. Ferrell, S. F. and W . G. Ferrell Jr. (1994 ) , "Using quality function deployment in business planning at a small appraisal firm", The Appraisal Journal, Vol. 62, No. 3, pp. 382-390. Cohen, L. (1995) , Quality function deployment: how to make QFD work for you, Addison-Wesley Publishing Company, Massachusetts, USA. Guinta, L. R. and N . C. Praizler (1993) , The QFD book: the team approach to solving problems and satisfying customers through quality function deployment, Amacom, New York. Pr asad, B. (1995) , "JIT quality matrices for strategic planning and implementation", International Journal of Operations and Production Management, Vol. 15, No. 9, pp. 116-142. Lu, M. H., C. N. Madu, C. Kuei and D. Wino kur ( 1994) , "Integrating QFD, AHP and benchmarking in strategic marketing", Journal of Business and Industrial Marketing, Vol. 9, No. 1, pp. 41-50. •
•
•
•
•
•
•
•
•
Atkins , A. R. and L . M. Crisafi (1995) , "Monopolize your strategy with QFD", Transactions from the Seventh International Symposium on Quality Function Deployment, Novi, Michigan, pp. 227-236. Lu, M. H. and C. Kuei (1995) , "Strategic marketing planning: a quality function deployment approach", International Journal of Quality and Reliability Management, Vol. 12, No. 6, pp. 85. Day, R. G. (199 1) , "Using the QFD concept in non-product related applications", Transactions from the Third International Symposium on Quality Function Deployment, Novi, Michigan, pp. 231-241. Chen, C. and S. F. Bullington (1993) , "Development of a strategic research plan for an academic department through the use of quality function deployment", Computers and Industrial Engineering, Vol. 25, Nos. 1-4, pp. 49-52. Low e A. J. and K. Ridgway ( 1998) , "Using Quality Function Deployment within Manufacturing SMEs", Proceedings of the 1st International SMESME Conference, 20-22nd April, The University of Sh effield, pp. 1-8. Barnard, B. (1992) , "Using quality function deployment to align business strategies and business processes with customer needs", Transactions from the Fourth International Symposium on Quality Function Deployment, Novi, Michigan, pp. 514-525. Lyman, D., R. F. Buesinger an d J. P. Keating (1994) , "QFD in strategic planning", Quality Digest, Vol. 14, No. 5, pp. 45-52. Hales, R. F. (1995) , "Quality function deployment as a decision making tool", Proceedings of the 38th APICA International Conference and Exhibition, Orlando, Oct 22nd-27th, pp. 489-492. Hales, R. F. (1997) , "Strategic selection of projects", APICS - The Performance Advantage, Dec, 7/12, pp. 44-47. •
•
•
•
•
•
•
•
•
QFD References 1. Sulliv an, L.P., 1986 , "Quality Function Deployment", Quality Progress, June, pp 39-50. 2. Aka o, Y., Ed. 1990 , "Quality Function Deployment: Integrating Customer Requirements into Product Design", Translated by Glenn Mazur. Cambridge, MA: Productivity Press. 3. Hau ser, J.R. & Clau sin g, D., 1988 , "The House of Quality", Harvard Business Review, May-June, pp 63-73. 4. Kin g, B., 1989 , "Better Designs in Half the Time", Third Edition, GOAL/QPC, Methuen, Massachusetts. 5. Cohen , L., 1995 , "Quality Function Deployment: how to make QFD work for you", Addison-Wesley Publishing Company, Massachusetts. 6. Nak ui, S., 1991 , "Comprehensive QFD System", Transactions from the Third International Symposium on QFD, Novi, Michigan, pp 137-152. 7. Hale s, R.F., 1995 , "Adapting Quality Function Deployment to the U.S. culture", IIE Solutions, Oct. (27/10), pp 15.
8. Scanlan, J.P., W infield , A. & Smith G., 1994 , "Modelling the Design Process within the Aerospace Industry", Factory 200 - Advaned Factory Automation, 3-5 October, Conference Publication No. 398, IEE, pp 645-650. 9. Smith, J.A. & Angel i, I.I., 1995 , "The use of Quality Function Deployment to Help Adopt a Total Quality Strategy", Total Quality Management, Vol. 6, No. 1, March, pp 35-44. 10. Po olton , J. & Barclay, I., 1996 , "Concurrent Engineering Assessment: a Proposed framework", Journal of Engineering Manufacture, Proceedings of the Institution of Mechanical Engineers, Vol. 210, No. B4, pp 321-328. 11. Ven ess , P.J., Chido lue , G. & M edh at, S.S., 1996 , "Concurrent engineering infrastructure; tools, technologies and methods in British industry", Engineering Management Journal, Vol. 6, No. 3, pp 141-147. 12. Haze lrig g, G.A., 1996 , "The implications of Arrow's impossibility theorem on approaches to optimal engineering design", Journal of Mechanical Design, Vol. 118, June, pp 161-164. 13. Arrow , K.J., 1963 , "Social choice and individual values", 2nd Ed., John Wiley & Sons, New York. 14. P raha lad, C.K. & Ha mel , G., 1990 , "The core competence of the corporation", Harvard Business Review, Vol. 68, No. 3, May-June, pp 73-91. 15. Gallo n, M.R., Stillm an, H.M. & Coate s, D., 1995 , "Putting core competency thinking into practice", Research and Technology Management, Vol. 38, Part 3, May-June, pp 20-28. 16. Kirkw ood, D.H., 1994 , "Semisolid metal processing", International Materials Reviews, 39(5), pp 173-189. 17. Zairi, M. & Yo ussef, M.A., 1995 , "Quality function deployment - a main pillar for successful total quality management and product development", International Journal of Quality & Reliability Management, Vol. 12, No. 6, pp 9-23. 18. Sulliv an, L.P., 1988 , "Policy management through quality function deployment", Quality Progress, Vol. 21, Part 6, pp 18-20.
UK Based QFD Research Modelling the Design Process within the Aerospace Industry - a record of the development of QFD as a management tool to model the dynamics of the design process. This model is to be applied to the structural design of an aircraft wing. (Ref 8) The Use of Quality Function Deployment to Help Adopt a Total Quality Strategy - a House of Quality matrix is utilised to compare the requirements of quality assurance standard ISO 9000 with the philosophies of five leading quality gurus (Crosby, Deming, Feigenbaum, Ishikawa and Juran). Companies can utilise this tool to develop a suitable strategy for applying total quality by weighting the importance of each ISO 9000 requirement. (Ref 9)
Application of QFD in the Automotive Industry - a project to apply a QFD methodology to the design of a new generation electric latch system within an automotive component and systems supplier, has been undertaken by the Department of Quality and Process Improvement at Cranfield University. Concurrent Engineering Assessment - a study of new product development procedures used in UK firms suggested that QFD is most appropriate when a product is complex from both a manufacturing and a product end user's point of view. (Ref 10) Concurrent Engineering Infrastructure - a study of the tools, technologies and methods used to achieve concurrent engineering in British industry, highlighted a low level of adoption of QFD in the UK despite its potential and a high level of awareness. The authors conclude that this is due to the perceived complexity of QFD methodology and confusion over its application and benefits. (Ref 11) The Implications of Arrow's Impossibility Theorem - the use of "averaged" group preferences by techniques such as QFD is shown to lead to potentially highly erroneous results by the application of Kenneth Arrow's Impossibility Theorem. (Ref 12) Seven QFD Project Case Studies Including UK Organisations - a paper that describes the results of a questionnaire based survey of seven QFD projects in U.S. and UK organisations. The paper concludes with benefits achieved and common implementation problems encountered. (Ref 17) UK Applications of QFD
The following organisations have been recorded as practitioners of QFD in the UK: Rover ICI Black & Decker Ltd Philips PT.PMR (Telecom) Sonatest PLC Midland Pump Manufacturing Company Ultra Electronics Ocean Systems Integrated Design Control Systems Carnival Design and Manufacture Metalastik Dunlop Merlin Gerin Transformers MBC Advanced Sintering This site hopes to link to more details of commercial QFD activities in the near future.
International QFD Research QFD in Environmental Strategy Management - Marcio Tavares of Global Transporte Oceanico S.A. (based in Brazil) has investigated the use of QFD in the development of an organisation's environmental management system. He can be contacted (in English) at
[email protected].
A Guide To QFD Resources QFD Institute The QFD Institute. Home page of Quality Function Deployment Institute. The Official Source for QFD dedicated to the advancement of Quality Function Deployment. The institute organises forums and seminars, holds an annual symposium to publicise the latest QFD applications and administers the Akao Prize. International Council for QFD The International Council for QFD (ICQFD) aims to promote a united international effort in the development of QFD techniques. The council organises International Council for QFD (ICQFD) and promotes QFD research. Softw are Engineering Research Netw ork The University of Calgary - Software Engineering Research Network provide a report describing QFD and its application to software design. Three exercises designed to introduce students to the techniques of QFD are also provided. Glenn Mazur Glen Mazur is one of the leading figures promoting QFD in the U.S. His home page describes several application case studies as well as the services he can provide. GO A L / Q P C GOAL/QPC - Helping organizations and communities to grow and prosper since 1978 are one of the leading suppliers of quality related products in the U.S. and offer a range of QFD books and articles. Bob Hales - ProAction Development Inc. Provides has written nine articles including a description of the adaptation of QFD for the U.S. business culture (Ref 7) on a site which promotes the activities of his U.S. consultancy organisation.
Becker Associates Becker Associates: QFD, Strategic Planning, Teamwork & Organization Development a consultancy based in Colorado provide useful introduction s to QFD, the "House of Quality" matrix and other related techniques such as TRIZ and Hoshin Kanri. IP M - I nnovation Process Management IPMis an independent company based in Dorset that specialises in innovation management, and offers training and workshops i n QFD. More QFD Related Links Ian Ferguson Associates A leading UK company which offers training, consultancy and software in QFD product and process development. Ian Ferguson Associates 32 Woodbourne Augustus Road Birmingham B15 3PH England Tel. +44 (0) 121 684 0002 Email:-
[email protected] Books and Articles The most well known and widely read article on QFD is probably "The House of Quality" by Hauser and Clausing (Ref 3). This remains an excellent introduction to the benefits of QFD and describes the building of a "House of Quality" matrix for a car door. One of the best practical guides to QFD application is "Quality Function Deployment: how to make QFD work for you" by Lou Cohen (Ref 5) which is also available from UK bookstores. Total Quality Software provide a list of books relevant to QFD practitoners on their software promoting website. QFD Software Too ls Several software packages are available to QFD practitioners that facilitate the construction of matrices and other QFD techniques. Examples include : "QFD Designer" Software for Windows
Integrated Quality Dynamics Inc. - Company Profile, Research, News, Information, Contacts, Divisions, Subsidiaries, Business Associations supply "QFD Scope". Total Quality Software supply "QFD2000" as well as other TQM related products. ASI also supply "QFD2000". This page only reflects the views and awareness of the author and is not meant to be a comprehensive review of all the QFD resources available.
QFD Research at the U niversity of Sheffield The Manufacturing Research Group at the University of Sheffield has been involved in QFD based research since 1994. The focus of this research has been on developing non-conventional applications of QFD tools suited to meeting the needs of UK manufacturing organisations. These applications have sought to transfer the benefits of using QFD in the product development process into other areas of business activity where they are appropriate. The benefits of using QFD tools which are relevant to many UK businesses include : •
• • •
Improved communications (particularly between functions and hierarchy levels) Emphasis on involving and understanding the customer. Systematic analysis of complex business problems. Generation of innovative insights and opportunities.
Three QFD methods have been developed and applied in case studies : 1. Strategy formulation within an SME 2. Developing new product concepts from core competencies 3. Evaluating innovative processing technologies Other areas of ongoing QFD research include: •
•
Evaluating the implications of Arrow's Impossibility Theorem (Ref 12) for QFD practitioners. This theorem highlights that the use of "averaged" group preferences by techniques such as QFD can lead to highly erroneous results. A review of QFD use in strategic decision-making applications and a proposed matrix of strategic QFD tools.
