5. QFD (QUALITY FUNCTIONAL DEPLOYMENT)
Basically this relates the customer requirements (i.e., product specifications) to the product design parameters (i.e., final designs) mathematically. The result is a mathematically driven product redesign.
Also known as House of Quality
Identify the customers needs, wants and requirements, also known as the Voice Of the Customer (VOX).
This ensures that the product design decisions are based on the customer and not just on the perceived customer needs.
this should involve all groups in a company that get any feedback from customers. Special programs may also be set up to poll customers.
STEP 2: Customer Requirements Refinement
The how list should be expanded until each point is a measurable quantity (called the final-product-control-characteristic)
Step 3: Begin Laying out the Planning Matrix
************ INCLUDE FIGURE FROM pg 76 Eureka, W.E., "Quality Functional Deployment Simplified", Technical Report, American Supplier Institute, Michigan, 1987.
STEP 4: Fill out the Correlation Matrix to determine how factors relate,
- relate positive changes to any one of the Control Characteristics to the others. In this case 1 is a very negative effect, up to 4 which is a very positive effect. Unrelated factors have no entry.
- If too many, or too few of these spots are filled, the customer requirements should be reexamined for accuracy, etc.
- The product and process should be reconsidered if in general there are more negative than positive effects.
STEP 5: Complete the relationship matrix and importance rating values.
- The relationships between the "WHATS" and "HOWS" are made in this matrix by assigning weights. For example 0-9 where 0 is none and 9 in very strong.
STEP 6: Customer Importance Rating and Market Evaluations
- The opinions of the customer (as collected in step 1) are quantified in terms of importance of the requirements "WHAT"s, these numbers are entered in the customer importance rating column.
- The overall ratings for the competitors products, as well as yours are ranked for each requirement "WHAT" as poor to good. These values are derived from information gathered in step 1, and entered in the Market Evaluations column.
- these sections will clearly identify the strengths and weaknesses of the product within the consumers objectives and compared to the competition.
STEP 7: Control Characteristics Competitive Evaluation
- Competitors products, and the internal product are compared technically. The performance criteria are done in terms of the Final Product Control Characteristics.
- Values are entered in the Control Characteristics Competitive Evaluation section of the chart, and are ranked good to poor.
- when these numbers are compared to the numbers in the Importance rating row, the technical deficiencies of the product, and it's importance are clear.
- the control characteristics competitive evaluation, and the importance rating should indicate candidates for change. Primarily a high importance rating, where the competitors product is rated better.
- the candidates selected should be checked to see how the correlate to the Customer Importance Rating and market evaluations. If the choice is not considered important to the customer, or less important then consider it less important. (Use the planning matrix to find effects).
- If any of the customer requirements are unanswered, then the requirements/control characteristics list must be reconsidered.
STEP 9: Develop new target values
- using current implemented design parameters, and the relative importance exposed in the last step, new target values should be selected.
- the values determined for the competitors products should be used as well as in-house data for the product.
- considering the target values and previous production performance, the difficulty of achieving the target value should be estimated.
- one or more factors can be selected. If there are not a few clear choices, the process should be reexamined
- the main objectives here are to select the elements with the lowest technical difficulties, but the greatest importance ratings
- this decision will be slightly arbitrary, but it should not be far outside of what the chart suggests.
- the control characteristics measured for all products, and the target values are positioned below.
- the bottom matrix is system components that can be affected by design. On the left are the systems they affect, and the components in those systems. On the right are the measurable variables, and in the centre are the locations to track the relative quality of the components.
- the deployment matrix is used to do design work, test the results, and compare them to the target values
Note that this process is involved, and will require some period of time, but will improve competitiveness of products.