Ship Repair Process with Quality Function Deployment Method

Quality Function Deployment
Quality Function Deployment

Quality Function Deployment (QFD)

Quality Function Deployment is a method used to plan and develop products or services that are structured to clearly determine the needs and desires of consumers [Cohen, 1995]. Basically QFD is a set of matrices that are used as a basis for decision making in product development. In QFD it is possible to focus on the needs of consumers so that it is expected to be able to reduce the cost of redesign or re-modification of the product, so that savings can be made as well as increase revenue because the product enters the market faster.

Consumer desires can be obtained in various ways including :

  • Routine and measured data collection obtained from consumer surveys, marketing surveys, trade trials and others. This data serves to convey information to the company about its performance in the market today.

  • Collection uses focus groups. Routine and subjective data collection obtained from focus groups. This method is usually used to find out things that are liked, disliked, trends and opinions of consumers about current and future products.

  • Subjective and random (random) data collection is usually obtained from trade visits, consumer visits, independent consultants. Where in concluding this type of data must be careful.

  • Data collection from meetings, suppliers and employees. This data is very valuable which usually truly represents the real consumer voice.


QFD uses several forms of matrices that are combined together, where each matrix creates different specific information. By combining these matrices into a single unit, a relationship between one information and another information about the quality attributes or characteristics of a product will be obtained. The product development process begins with the formation of a product planning matrix, called the House of Quality. Quality houses consist of several rooms, as shown in Figure 2.1 below :

Figure 2.1 House of Quality
Figure 2.1 House of Quality

1) Room A : WHATs,

Customer requirements contain information about consumer desires. The consultant defines what constitutes WHATs in quality homes. Consumer Voice (Voice of CustomerNOC) is a basic requirement. At first the consumer is heard what he wants, and set forth in the list of consumer needs and expectations. WHATs is a collection of what they want, or what consumers like about the product today.

2) Room B : WHYs , manufacturing factor for WHATs

Contains three types of data, namely:

a. Data sequence of the level of importance (ranking) needs and desires of consumers. WHA Ts weighting to set priorities, what is significant, what is not on the WHATs list.

b. Consumer level data on enterprise products and competitor products. Contains a list explaining the importance of current competitive products that refer to world class products or current competitive products that refer to world class products or the best products in their class. WHYs can state the name of a competitor, competitor’s product, market segment, or other matters. Which explains the current market conditions, compared to the company itself.

c. Strategic objectives for the product or service to be developed (potential market).

3) Space C: HOWs, quality characteristics.

This space contains technical requirements for new products being developed. Data is sorted from information obtained through the needs and desires of consumers of space A. The QFD team defines what constitutes HOWs (Technical Responses) in quality homes.

  • HOWs are a set of quality characteristics in realizing a collection of WHATs obtained from market research.

  • HOWs show the design variables and alternative solutions that are mutually independent or not. Each HOWs provides a solution or an alternative to solve one or more WHATs.
  • HOWs provide an operational definition of quality characteristics that are mutually independent or not. Each HOWs provides a solution or alternative to solve one or more WHATs.

  • HOWs are a method / technical in translating consumer voices into design criteria. A WHATs can be responded to by several HOWs.

  • HOWs are a set of quality characteristics to satisfy consumer desires or expectations (WHATs). HOWs can also be called quality characteristics. Types of HOWs can be length, width, height, thickness, volume, and all.

4) Room D : WHATs Vs HOWs

Correlation between consumer desires with technical requirements (quality characteristics). Contains management’s assessment (QFD team) about the strength of the relationship between the elements contained in the technical requirements section with the desires and needs of the consumers it influences. The matrix contained in the rectangular area connects what consumers want with a product and how the company achieves that goal. The WHATs and HOWs relationship matrix is ​​the core correlation matrix in QFD. Relationships in the matrix are usually defined using strong, medium, weak or non-existent levels as set out in table 2.1.

ITEM Hubungan Kuantitatif Kualitatif
WHATs dengan HOWs Level Weight Symbol
Strong relationship 9 Solid circle  ●
Moderate relationship 3 Open circle ○
Weak relationship 1 Open triangle ∆
Not 0 Empty

The table above illustrates the relationship between quality attributes and technical responses. Figure 9 shows that the relationship between quality attributes and technical response is very strong and symbolized by a solid circle, while number 0 indicates that there is no relationship between quality attributes and technical response.

5) Roof E : HOWs Vs HOWs matrices

The relationship between quality characteristics. This section states the correlation between one technical requirement and other technical requirements. The correlation between the two technical statements is associated with symbols as shown in table 2.1. the aim is to identify qualitative relationships between item characteristics (HOWs) because sometimes, the solutions are too excessive and may not add value to what consumers expect, also sometimes the goals cross with each other. This section has several categories of relationships including:

  • Positive or strong positive if both HOWs help each other to meet the target value (How muches).
  • Negative or strong negative if meeting one HOW makes it difficult for the other HOWs to meet the target.

6) Space F : HOWs with HOW MUCHes

This section is a feasibility matrix to help the team decide how many HOWs might be realized to meet the wishes of the consultants. Contains the following data :

  • The order of importance of technical requirements.
  • Information on the results of the comparison of the technical requirements of the company’s and competitors.
  • Performance target technical requirements for the product being developed.

Read more : Ship Design TheoryCost component of ship repair


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