QUALITY FUNCTION DEPLOYMENT A tool for customer-focused design of products and services Paul Roberts Principal Fellow Quality & Reliability Warwick Manufacturing Group University of Warwick paul.roberts@warwick.ac.uk
RELATIO NSHIPS 9 STRONG 3 MEDIUM 1 WEAK MAX MIN TARGET WORSE BET TER 4 CORRELATION STRONG + POSITIVE NEGATIVE STRONG - 1 2 3 4 5 The QFD chart RELATIONSHIPS 9 STRONG 3 MEDIUM 1 WEAK MAX MIN TARGET CORRELATION STRONG + STRONG NEGATIVE STRONG - HOWs WHATs IMPORTANCE Width of armrest Armrest recess depth Armrest recess width Height of back Profile of back Back thickness Pan height Foam stiffness Foam thickness WORSE CUSTOMER RATING BETTER 1 2 3 4 5 Arm rest folds right away 5 Arm rest wide enough Enough leg room 5 8 Doesn't cause bum ache 8 Tall person shoulder comfort 7 Short person lumbar comfort 7 IMPORTANCE 90 45 45 68 222 87 96 114 114 Our Company OBJECTIVE TARGET VALUES 50mm 80mm 55mm 1080mm T.B. I. COMPETITIVE ASSESSMENT BETTER 5 4 3 2 WORSE 1 TECHNICAL & REGULATORY REQUIREMENTS FST 1000 Max. deflection MARKET QUALITY REQUIREMENTS Passengers Feel Comfortable Comfortable Reclined Comfortable Upright Cost Low Service Costs Low Operatin g Costs ENGINEERING CHARACTERISTICS Item Number IMPO RTANCE Arm rest fold right away 5 Arm rest wide enough 5 Enough leg room 8 Doesn't give you bum ache 8 Doesn't hurt the shoulders of a taller person 7 Lumbar support doesn't hurt shorter person 7 Doesn't hit person behind when you recline 7 Back can be adjusted to any position and doesn't slip 8 Doesn't soak up spilt drink 5 Easy to clean 6 Fabric stain resistant 6 Durable 6 Light weight 9 Easy to move around 4 Fit more passengers in 5 Armrest Back Fabric Structure All Foam Mountings Width of armrest Armrest recess depth Armrest recess width Height of back Profile of back Profile of pan Back thickness Pan height Back hinge location Loci of hinge Clutch locking force Clutch resistance (open) Fabric tear resistance Fabric wear resistance Washable fabric Stain resistant fabric Liquid resistant fabric Fatigue performance Structural strength Structural stiffness Material FST performance Foam stiffness Foam t hickness Mountings interchangeable Number of fasteners Location of fasteners 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 SERVICE COMPLAINTS 5 12 3 3 5 2 8 CUSTOMER RATING WORST BEST DEGREE OF TECHNICAL DIFFICULTY 1 2 4 2 4 4 5 3 3 5 4 4 4 3 2 4 4 4 4 4 4 2 2 1 3 1 TECHNICAL TARGETS 50 mm 80 mm 55 mm 580 mm T.B.I. T.B.I. 25 mm 450 mm x= 150, y= 50 T.B.I. 100 N 5 N 3 mm Test 1x10 6 strokes 100 washers Test 013 1 gm/hr 1x10 6 cycles 7000 N Test 70 mm at 7000 N 5 min + 20 MN/m 2 25 mm Interchange Over rails = A = B = C TECHNICAL COMPETITIVE COMPARISONS 1 2 3 4 5 Technical and Regulatory Requirements FST 1000 16 G LOAD CASE MAX ALLOWABLE DEFLECTION INTERFACE TO FLOOR RAILS Eng Char. Importance Ratings ABSOLUTE RELATIVE 114 54 54 182 290 24 204 105 87 63 81 72 54 54 54 108 117 81 135 81 27 120 123 36 63 36 5 2 2 8 12 1 9 4 4 3 3 3 2 2 2 5 5 3 6 3 1 5 5 2 3 2
QFD the issues Remoteness from the final customer. Lack of visibility of the customer chain. Informal (or inappropriate) customer requirement definition. Complex technologies. Technology-led products. Unclear relationship between customer requirements and technology. QFD provides: A structured approach. A strong customer focus. A tool which is applied early in the product life cycle. Coverage of the whole process. A framework for cross-functional teamwork. A record of design/production decisions.
Definition of QFD A system for translating customer requirements into company requirements at each stage, from research and development through engineering and manufacturing to marketing, sales and distribution. Source: American Suppliers Institute Definition of QFD Practically this means that it provides a mechanism for targeting and prioritising design effort to give maximum customer satisfaction. In manufacturing this will focus on the design of the product. In service organisations it will be the design of the service.
The Customer Chain There is rarely only one level of customer for a product. For example, the customer chain for a breakfast cereal would be: distributor, wholesaler, retailer, purchaser and consumer. All of these customers must be taken into account for a successful design. They may be given a different weighting in case of conflict. Information flow from the customer
The Kano Model Of Quality Customer Satisfaction Excitement Quality (unspoken) Degree of Achievement Spoken Performance Basic Quality (unspoken) Who is the customer in QFD?
Sources of Information for QFD Postal questionnaires. Interview questionnaires. Clinics. Focus groups. Listening. Unsuitable sources of information Government statistics. Surveys. Reports. Trade and business papers.
Customer requirements Technical & Regulatory Requirements
Technical & Regulatory requirements National regulations EC regulations Local regulations British Standards, International Standards etc Automated manufacture Size restrictions Why organize customer requirements? Simplify later use of charts Team reaches a common understanding Identify areas missed by the sampling of customer needs
How to Create an Affinity Diagram Team brainstorms ideas Normal rules apply Each idea is written on a single card Cards are laid out on a wall or table Ensure sufficient access for all team members The cards are moved into like piles Low motivation High absenteeism Acceptance of defects Lack of teamwork 1 2 3 4 Short-term attitude 6 High internal barriers Low pride in work Lack of vision 5 7 8 Lack of innovation 9 Poor 10 management of change Poor 11 internal communication 12 Management by fear How to Create an Affinity Diagram Team brainstorms ideas Normal rules apply Each idea is written on a single card Cards are laid out on a wall or table Ensure sufficient access for all team members The cards are moved into like piles Cards that do not fit into any pile may be grouped in a miscellaneous pile Low motivation High absenteeism Acceptance of defects Low pride in work 1 2 3 7 Lack of teamwork 4 6 High internal barriers Poor 11 internal communication Lack of innovation Poor 10 management of change Lack of vision 9 8 12 Management by fear 5 Short-term attitude
How to Create an Affinity Diagram Cards may be duplicated if necessary When team members no longer wish to move cards Each pile is given a title The grouping process is repeated for the titles The groups of titles are given a title LOW MORALE Low motivation High absenteeism Acceptance of defects Low pride in work POOR INTER- DEPARTMENTAL RELATIONSHIPS Lack of teamwork High internal barriers Poor internal communication POOR LEADERSHIP Lack of innovation Poor management of change Lack of vision Management by fear Short-term attitude The Completed Diagram Poor Employee Satisfaction Low Morale Poor Interdepartmental Relationships Poor Leadership Low motivation Low pride in work High absenteeism Acceptance of defects Lack of teamwork High internal barriers Poor internal communication Short-term attitude Lack of vision Lack of innovation Poor management of change Management by fear
Practical Hints Group cards in silence Do not attempt to name the piles before grouping has been completed The name of the group should be a short phrase rather than a single word Single word titles tend to lose their meaning The name of the group may come from a card in the pile Finally, Discuss the Diagram The team should discuss the diagram To gain a better understanding of the topic and the relationships between different aspects of the topic To identify areas missed during brainstorming
Affinity Diagram Customer and technical/ regulatory requirements MARKET QUALITY REQUIREMENTS PRIMARY Passengers Feel Comfortable SECONDARY Comfortable Upright Comfortable Reclined TERTIARY Arm rest folds right away Arm rest wide enough Enough leg room Doesn't give you bum ache Doesn't hurt shoulders of taller person Lumbar support doesn't hurt shorter person Doesn't hit person behind when you recline Back can be adjusted to any position and doesn't slip Cost Low Service Costs Low Operating Costs Doesn't soak up spilt drink Easy to clean Fabric stain resistant Durable Light weight Easy to move around Fit more passengers in Technical and Regulatory Requirements FST 1000 16 G LOAD CASE MAX ALLOWABLE DEFLECTION INTERFACE TO FLOOR RAILS
Establishing Customer Importance Ratings & Customer Competitive Comparisons Importance Ratings and Competitive Comparisons
Obtaining Customer Ratings & Comparisons Postal questionnaires Telephone interviews Face to face interviews Clinics Focus groups Listening Customer questionnaire BIG PIZZAS LTD For the Pizza you have just eaten please tell us how important the following items were to you and please tell us how you rate your satisfaction with each item. How important is this item How do you rate our Pizza on this item PLEASE RATE LOTS OF CHEESE Not important Not very important Important Very important Extremely important Poor Fair Good Very good Excellent 1 2 3 4 5 1 2 3 4 5 VARIED CHOICE OF CHEESE 1 2 3 4 5 1 2 3 4 5 NO ANCHOVIES 1 2 3 4 5 1 2 3 4 5
Customer importance ratings & competitive comparisons Customer complaint history
Customer complaint history Establishing engineering characteristics What I want is 1, 2, 3 To achieve this we will need x, y, z.
Engineering characteristics Engineering characteristics
Technical competitive comparisons Provide hard facts Focus on the market Give the impetus to improve Technical competitive comparisons
Technical competitive comparisons aircraft seat study Engineering characteristics grouping data Human requirements Process requirements Engineering characteristics Units of measurement Train assembly staff to attach covers on the back and side of seat only. Wipe excess adhesive off seat structure during assembly. Grind off any lumps of set adhesive after assembly. Seat gap width Seat gap depth Arm rest width Seat back thickness Seat back profile Seat pan profile Seat pan height Foam thickness Foam hardness mm mm mm mm mm (x,y,z) mm (x,y,z) mm Mm Vickers
Engineering characteristics Engineering characteristics Company (A = us) Measured data Average value Value selected as normal Value on 1-5 scale Seat back thickness A B C 28 mm 36 mm 25 mm 29.6 30 3.2 2.5 3.6 Seat back profile A B C Smooth, doubly curved Flat Smooth, singly curved - 4 1 3 Relationships
Establishing Links Highlights the relationship between: Customer requirements and engineering characteristics Technical and regulatory requirements and engineering characteristics The symbols used are: Strong relationship Medium relationship Weak relationship Establishing Engineering Characteristics Importance Ratings Values assigned to relationship symbols: Strong relationship = 9 Medium relationship = 3 Weak relationship = 1
Establishing links relationships matrix Establishing links correlation matrix STRONG PO SITIVE RELATIONSHIP POSITIVE RELATIONSHIP NEGATIVE RELATIONSHIP STRONG NEGATIVE RELATIONSHIP Armrest Back Fabric Structure Width of armrest Armrest recess depth Armrest recess width Height of back Profile of back Profile of pan Back thickness Pan height Back hinge location Loci of hinge Clutch locking force Clutch resistance (open) Fabric tear resistance Fabric wear resistance Washable fabric Stain resistant fabric Liquid resistant fabric Fatigue performance Structural strength Structural stiffness Material FST Performance All Foam stiffness Foam thickness Mountings interchangeable Number of fasteners Location of fasteners Foam Mountings Item Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Foam thickness Establishing technical targets and ratings ENGIN EERIN G CHARACTERISTICS Armrest Back Fabric Structure All Foam Mountings MARKET QUALITY REQU IREMEN TS PRIMARY Passengers Feel Comfortable SECONDARY Comfortable Upright Comfortable Reclined Cost Low Operating Low Service Costs Costs DEGREE OF IMPORTANCE TERTIARY Item Number Width of armrest Armrest recess depth Armrest recess width Height of back Profile of back Profile of pan Back thickness Pan height Back hinge location Loci of hinge Clutch locking force Clutch resistance (open) Fabric tear resistance Fabric wear resistance Washable fabric Stain resistant fabric Liquid resistant fabric Fatigue performance Structural strength Structural stiffness Material FST Performance Foam stiffness Mountings interchangeable Number of fasteners Location of fasteners 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Arm rest folds right away 5 Arm rest wide enough 5 Enough leg room 8 Doesn't give you bum ache 8 Doesn't hurt shoulders of taller person 7 Lumbar support doesn't hurt shorter person 7 Doesn't hit person behind when you recline 7 Back can be adjusted to any position and doesn't slip 8 Doesn't soak up spilt drink 5 Easy to clean 6 Fabric stain resistant 6 Durable 6 Light weight 9 Easy to move around 4 Fit more passengers in 5 ABSOLUTE ENG. CHAR. IMPORTANCE RATINGSRELATIVE 114 54 54 182 290 24 204 105 87 63 81 72 54 54 54 108 117 81 135 81 27 120 123 36 63 36 5 2 2 8 12 1 9 4 4 3 3 3 2 2 2 5 5 3 6 3 1 5 5 2 3 2 Technical Targets & Engineering Importance Rating
Establishing Technical Targets and Ratings Determine target values for the Engineering Characteristics. Determine the technical difficulty of achieving the target value. (1=easily 5=very difficult) Calculate the Importance Rating. Establishing technical targets
Establishing the degree of difficulty DEGREE OF TECHNICAL DIFFICULTY 1 2 4 2 4 4 5 3 3 5 4 4 4 3 2 4 4 4 4 4 4 2 2 1 3 1 TECHNICAL TARGETS 50 mm 80 mm 55 mm 580 mm T.B.I. T.B.I. 25 mm 450 mm x= 150, y= 50 T.B.I. 100 N 5 N 3 mm Test 6 1x10 strokes 100 washers Test 013 1 gm/hr 6 1x10 cycles 7000 N Test 70 mm at 7000 N 5 min + 20 MN/m 2 25 mm 4 1 = easily, 5 = very difficult Interchange Over rails TECHNICAL COMPETITIVE COMPARISONS Worse Best 1 =A 2 =B 3 =C 4 5 Analysis of Chart
Benefits of QFD Less time in development. Fewer and earlier changes. Fewer start-up problems (and costs). Fewer field problems. Improved customer focus (and satisfaction). Better targeted design and development. A better knowledge base. Practical points Requires management commitment. Success is determined by the accuracy of customer requirements. Always start small. Involve the right people. Matrix analysis can be used for any decisionmaking process.
The QFD team (manufacturing) Designers. Marketing. Manufacturing engineers. Sales support. Manufacturing. Production control. Quality. Maintenance. Suppliers. QFD cascade Design Requirements Production Requirements Customer Requirements Part Characteristics Part Characteristics Manufacturing Operations Design Requirements Manufacturing Operations
Things to do next Agree project. Establish scope, limitations and constraints. Establish objectives. Agree approximate resources, timing and milestones. Agree team session format. Agree methods of data collection. Gather customer data.