Understanding Customer Requirements Principles of Design Zahed Siddique Assistant Professor School of Aerospace and Mechanical Engineering University Of Oklahoma zsiddique@ou.edu

Need to focus Moving in the wrong direction at a fast pace is still moving in the wrong direction. Right Wrong

Information on QFD…. Developed in Japan in the mid 1970s Introduced in USA in the late 1980s Toyota was able to reduce 60% of cost to bring a new car model to market Toyota decreased 1/3 of its development time Used in cross functional teams Companies feel it increased customer satisfaction

Why….? Product should be designed to reflect customers’ desires and tastes. House of Quality is a kind of a conceptual map that provides the means for interfunctional planning and communications To understand what customers mean by quality and how to achieve it from an engineering perspective. HQ is a tool to focus the product development process

QFD Target

Important points Should be employed at the beginning of every project (original or redesign) Customer requirements should be translated into measurable design targets It can be applied to the entire problem or any subproblem First worry about what needs to be designed then how It takes time to complete

Components of House of Quality Hows vs Hows Components of House of Quality Customer Evaluation Who Hows Now This Product Who vs. Whats Whats Whats vs Hows Now vs What Units Hows vs How Muches How Muches This Product Targets Targets

Extensions to House of Quality Customer Evaluation Ratio of Improvement Useful Data Target This Product Weighted Importance Importance % Units This Product Targets Technical Difficulty

Step 1: Who are the customers? To “Listen to the voice of the customer” first need to identify the customer In most cases there are more than one customer consumer regulatory agencies manufacturing marketing/Sales Customers drive the development of the product, not the designer

Step 2: Determine the customers’ requirements Need to determine what is to be designed Consumer product works as it should lasts a long time is easy to maintain looks attractive incorporated latest technology has many features List all the demanded qualities at the same level of abstraction

Step 2: cont... Manufacturing Marketing/Sales easy to produce uses available resources uses standard components and methods minimum waste Marketing/Sales Meets customer requirements Easy to package, store, and transport is suitable for display

Kano Model Basic Quality: These requirements are not usually mentioned by customers. These are mentioned only when they are absent from the product. Performance Quality: provides an increase in satisfaction as performance improves Excitement Quality or “wow requirements”: are often unspoken, possibly because we are seldom asked to express our dreams. Creation of some excitement features in a design differentiates the product from competition.

Types of customer requirements Functional requirements describe the product’s desired behavior Human factors Physical requirements Reliability Life-cycle concerns Resource concerns Manufacturing requirements

How to determine the Whats? Customer survey (have to formulate the questions very carefully) If redesign, observe customers using existing products Combine both or one of the approaches with designer knowledge/experience to determine “the customers’ voice”

Affinity Diagram Provides structure for verbal data by creating natural clusters or groups Ensures that the list of demanded qualities are complete and expressed at the same level of detail

Constructing Affinity Diagram Set a brainstorming session to list all possible requirements Record each element of the list on small cards Place all cards on a table randomly Silent mode Spend time reading all demanded qualities Start at the same time, once everyone is ready - everyone quickly and without thought find two demanded qualities that have something in common If you find a demanded quality is not where you think it belongs, move it. If it is moved again, make a duplicate and talk about it later. The process continues until all demanded qualities are in a group.

Constructing Affinity Diagram Discussion Mode Begin discussion after group composition for the demanded qualities becomes stable First review the demanded qualities that seemed to have more than one home Select a descriptive name for the groups. Group names must also be demanded qualities, but at a higher level of abstraction Look at each group and judge if all elements are at the same level of abstraction Check each group by asking “If this is the name of the group, what elements should be included but are missing?” Next test for missing groups. Check with the types of customer requirements list

Step 3: Determine Relative Importance of the Requirements: Who vs. What Need to evaluate the importance of each of the customer’s requirements. Generate weighing factor for each requirement by rank ordering or other methods Hows vs Hows Customer Who Evaluation Hows Now This Product Whats Who vs. Whats Whats vs vs What Hows Now Units Hows vs How This Product Muches How Muches Targets Targets

Rank Ordering Order the identified customer requirements Assign “1” to the requirement with the lowest priority and then increase as the requirements have higher priority. Sum all the numbers The normalized weight Rank/Sum The percent weight is: Rank*100/Sum

Step 4: Identify and Evaluate the Competition: How satisfied is the customer now? The goal is to determine how the customer perceives the competition’s ability to meet each of the requirements it creates an awareness of what already exists it reveals opportunities to improve on what already exists Hows vs The design: 1. does not meet the requirement at all 2. meets the requirement slightly 3. meets the requirement somewhat 4. meets the requirement mostly 5. fulfills the requirement completely Hows Customer Who Evaluation Hows Now This Product Whats Who vs. Whats Whats vs vs What Hows Now Units Hows vs How This Product Muches How Muches Targets Targets

Step 5: Generate Engineering Specifications: How will the customers’ requirements be met? The goal is to develop a set of engineering specifications from the customers’ requirements. Restatement of the design problem and customer requirements in terms of parameters that can be measured. Hows vs Hows Customer Who Evaluation Each customer requirement should have at least one engineering parameter. Hows Now This Product Whats Who vs. Whats Whats vs vs What Hows Now Units Hows vs How This Product Muches How Muches Targets Targets

Step 6: Relate Customers’ requirements to Engineering Specifications: Hows measure Whats? This is the center portion of the house. Each cell represents how an engineering parameter relates to a customers’ requirements. 9 = Strong Relationship 3 = Medium Relationship 1 = Weak Relationship Blank = No Relationship at all Hows vs Hows Customer Who Evaluation Hows Now This Product Whats Who vs. Whats Whats vs vs What Hows Now Units Hows vs How This Product Muches How Muches Targets Targets

Engineering specifications maybe dependent on each other. Step 7: Identify Relationships Between Engineering Requirements: How are the Hows Dependent on each other? Engineering specifications maybe dependent on each other. 9 = Strong Relationship 3 = Medium Relationship 1 = Weak Relationship -1 = Weak Negative Relationship -3 = Medium Negative Relationship -9 = Strong Negative Relationship Blank = No Relationship at all Hows vs Hows Customer Who Evaluation Hows Now This Product Whats Who vs. Whats Whats vs vs What Hows Now Units Hows vs How This Product Muches How Muches Targets Targets

Step 8: Set Engineering Targets: How much is good enough? Determine target value for each engineering requirement. Evaluate competition products to engineering requirements Look at set customer targets Use the above two information to set targets Hows vs Hows Customer Who Evaluation Hows Now This Product Whats Who vs. Whats Whats vs vs What Hows Now Units Hows vs How This Product Muches How Muches Targets Targets

Relationships Among Engineering Characteristics Identifying performance measure conflicts Customer Evaluation Customer Evaluation Record customer performance ratings for your Similar product and competitors’ products Engineering Characteristics Record Performance measures for each customer demanded quality Customer Evaluation Relative Importance Importance for each demanded quality needs to be determined Customer Attributes The first step is to list all the demanded qualities at the same level of abstraction Engineering Influence Customer Qualities Relationship between demanded customer qualities and Engineering Performance Objective Measures Units Technical benchmarking Determining Important Characteristics Technical Difficulty Importance Technical Difficulty associated with achieving Targets/improvements and importance of technical characteristics Units Targets Setting Technical Targets Targets Technical Difficulty Importance

Components of House of Quality Hows vs Hows Components of House of Quality Customer Evaluation Hows Who Now This Product vs Whats vs Whats Who vs. Whats What Hows Now Weighted Importance Importance % Addition to the House of Quality presented in text book Units Hows vs How This Product Muches How Muches Targets Targets Rank Technical Difficulty Selected

Creating the Requirement List Contents of Requirement List Specify if the individual items are demands or wishes in the clearest possible terms Tabulate Quantitative and Qualitative aspects Collect further information If possible rank wishes as being of major, medium or minor importance Living document Arrange the requirements in clear order Define the main objective and the main characteristics Split into identifiable groups Enter the Requirement list on standard forms and circulate Examine Objections

Requirement List

Requirement List Example Name 1 Name 2 Name 3 Requirement List Example Use information from House of Quality as an starting point for creating the requirement list. Need to identify requirements for the product that are basic and necessary but are not specified by the customers.

Example House of Quality Design a device to toast breads and other similar types of food