UNDERSTANDING THE PROBLEM AND THE DEVELOPMENT OF ENGINEERING SPECIFICATIONS

UNDERSTANDING THE PROBLEM AND THE DEVELOPMENT OF ENGINEERING SPECIFICATIONS

1. “Understanding the design problem”

   • Means to translate customers’ requirements into a technical description of what needs to be designed.

2. The design process focus on

   • Understanding the problem that is to be solved so it exist techniques used to generate engineering specifications like Quality Function Deployment (QFD)
     • This method consists on:
       • 1. Hearing the voice of the customers
       • 2. Developing the specifications or goals for the product
       • 3. Finding out how the specifications measure the customers’ desires
       • 4. Determining how well the competition meets the goals
       • 5. Developing numerical targets to work toward

3. QFD steps builds the house of quality

   • STEP 1: IDENTIFY THE CUSTOMERS: WHO ARE THEY?
     • For all products it is important to consider customers both outside the organizations that design, manufacture, and distribute the product—external customers—and those inside of them—internal customers.
       • One method to make sure you have identified all the customers is to consider the entire life of the product.
   • STEP 2: DETERMINE THE CUSTOMERS’ REQUIREMENTS: WHAT DO THE CUSTOMERS WANT?
     • Determine what is to be designed.
       • A product that works as it should, lasts a long time, is easy to maintain, looks attractive, incorporates the latest technology
         • And has many features
           • Easy to produce, easy to package, store, and transport.
     • The key to this step is collecting information from customers.
       • There are essentially three methods commonly used:
         • Observations, surveys, and focus groups.
     • Suggestions to get the best possible customers’ requirements:
       • Do not assume you know what the customer wants.
       • If customer requirements are too vague, then go back to the customer and flesh these out a little more in the customer’s words.
       • The only way they may have of expressing what they want is in terms of analogies and comparisons to other products.
       • Use Kano’s model to help you steer away from basic requirements to perfor- mance and excitement requirements.
       • Challenge, question, and clarify requirements
       • Document situations and circumstances to illustrate a customer need.
   • STEP 3: DETERMINE RELATIVE IMPORTANCE OF THE REQUIREMENTS: WHO VERSUS WHAT
     • To whom is the requirement important? And, How is a measure of importance developed for this diverse group of requirements?
       • It is essential to understand which requirements each type of customer thinks is important.
         • The best way to represent importance is with a number showing its weight relative to the other requirements.
           • If you collect weightings from more than one representative of a customer group and they are in fairly good agreement with each other, then just average them.
             • If weightings are significantly different, then this is a signal that you have two different types of customers and you need to revisit the step 1.
               • Requirements that measure basic needs are not helpful.
   • STEP 4: IDENTIFY AND EVALUATE THE COMPETITION: HOW SATISFIED ARE THE CUSTOMERS NOW?
     • The goal is to determine how the customer perceives the competition’s ability to meet each of the requirements.
       • For each customer’s requirement, we rate the existing design on a scale of 1 to 5:
         • 1. Does not meet the requirement at all. 
 2. slightly. 
 3. somewhat. 
 4. mostly. 
 5. Fulfills the requirement completely.
           • they do give an indication of how the competition is perceived by the customer, it shows opportunities for product improvement.
   • STEP 5: GENERATE ENGINEERING SPECIFICATIONS: HOW WILL THE CUSTOMERS’ REQUIREMENTS BE MET?
     • Develop a set of engineering specifications from the customers’ requirements.
       • Consist of parameters of interest and targets for parameters.
         • These specifications are a translation of the voice of the customer into the voice of the engineer.
           • Serve as a vision of the ideal product and are used as criteria for design decisions.
             • Design decisions affect the customer’s perception of the quality of their product.
               • We begin by finding as many engineering parameters as possible that indicate a level of achievement for customers’ requirements.
                 • The major types of specifications in this list are detailed next:
                   • Functional performance requirements
                   • Human factors requirements
                   • Physical requirements
                   • Product’s reliability
                   • Time requirements
                   • Cost requirements
                   • Standards
                   • Codes of practice
                   • Environmental concerns
                   • Manufacturing/Assembly requirements
   • STEP 6: RELATE CUSTOMERS’ REQUIREMENTS TO ENGINEERING SPECIFICATIONS: HOW TO MEASURE WHAT?
     • Many specifications will measure more than one customer’s requirement.
       • The strength of this relationship can vary, with some engineering specifications, providing strong measures for a customer’s require- ment and others providing no measure at all.
         • 9 = strong relationship
 3 = medium relationship
 1 = weak relationship
 0 = no relationship at all
   • STEP 7: SET ENGINEERING SPECIFICATION TARGETS
AND IMPORTANCE: HOW MUCH IS GOOD ENOUGH?
     • We set the targets and establish how important it is to meet each of them
       • There are three parts :
         • Specification Importance
           • Determining the importance for each specification
             • If is important, then effort needs to be expended to meet the target.
               • Effort needs to be expended to meet the target.
               • If it is not, then meeting the goal can be more easily relaxed.
         • Measuring How Well the Competition Meets the Specifications
           • Obtaining actual samples of the competition’s product and making measurements on them in the same way that measurements will be made on the product being designed
         • Setting Specification Targets
           • Setting targets early in the design process is important
             • Targets set near the end of the process are easy to meet but have no meaning, most targets are flexible and they may not be met during design.
           • Setting targets is to establish the levels at which the customers will be delighted and those where they will be disgusted.
   • STEP 8: IDENTIFY RELATIONSHIPS BETWEEN ENGINEERING SPECIFICATIONS: HOW ARE THE HOWS DEPENDENT ON EACH OTHER?
     • Engineering specifications may be dependent on each other.
       • It is best to realize these dependencies early in the design process.
         • As you work to meet one specification, you may be having a positive or negative affect on others.

4. FURTHER COMMENTS ON QFD

   • Ensures that the problem is well understood.
   • It is useful with all types of design problems and results in a clear set of customers’ requirements and associated engineering measures