We use two core tools, FMEA and QFD.

Part 1. What is FMEA?

In failure mode analysis, FMEA is composed of failure mode analysis (FMA) and failure effect analysis (FEA). It is one of the important reliability design methods. FMEA focuses on prevention. Its main purpose is to find potential failure modes in products / processes, evaluate their consequences and risks, formulate corresponding prevention / detection measures, modify products or processes, avoid or reduce the occurrence of potential failure modes, and avoid or reduce the crisis and cost caused by subsequent modification.

Failure refers to the partial or total loss of the ability of the process, product or system to complete its function. Potential failure is a failure that may occur. Failure consequence refers to the impact of failure on part performance and the impact of failure on customer use. FMEA can be divided into Design FMEA, Process FMEA, equipment FMEA and system FMEA. The most commonly used are Design FMEA and Process FMEA. The specific differences are as follows:

1) DFMEA

Design FMEA, which is used for reliability analysis in product design. The analysis object is the final product and relevant parts department, subsystem or system. DFMEA generally starts to intervene at or before the formation of design probability. In each stage of product development, when the design changes or other information changes, it will be updated in time, and it will end before the sample processing and verification are successful.

2) PFMEA

Process FMEA, which is used for reliability analysis in process design. The analysis objects are new products / processes and changed products / processes. Generally, PFMEA is used before the preparation of production tooling until the product is officially put into production. After putting into production, PFMEA should be continuously updated according to the changes of production process. 3. EFMEA: equipment FMEA, used for equipment reliability analysis; 4. SFMEA: system FMEA, used for system reliability analysis.

Part 2. The role of FMEA?

As a reliability tool, FMEA is used to:

1. FMEA can systematically analyze and summarize and form documents during product design or process design;

2. FMEA can reduce the risk of product failure. The reason is that FMEA finds out the potential failure mode and formulates prevention / detection measures to prevent failure;

3. FMEA team members can complete FMEA analysis in the early design process to improve the reliability of product design. The team members include the heads of design engineers, quality engineers, process engineers and other departments to better gather the wisdom of the team;

4. FMEA can take preventive or detection measures in advance to reduce or eliminate greater losses caused by design modification or process change;

5. FMEA is “ex ante behavior”, not “ex post behavior”; In FMEA analysis, timely detection of risks can make it easier and cheaper to rectify products or processes, so as to reduce the crisis of subsequent modification;

6. The application of FMEA (DFMEA and PFMEA) is an interactive and endless process.

Part 3. What are the characteristics of FMEA?

FMEA is a systematic tool, which is characterized by:

1) A prior act;

2) A cyclic process;

3) A product of multi-party argument;

4) Structured approach;

5) Qualitative and subjective;

6) Emphasize the tracking of measures;

7) Reduce maintenance costs and recall.

Part4. What is QFD?

Quality Function Deployment (QFD) is mainly used to identify the needs of customers or markets and convert these requirements into product features / functions / requirements. QFD is a tool that links all R & D, engineering and manufacturing work with customer requirements (VOC). QFD is actually a highly operational method. Its key is to build a house of quality. Now let’s see how to do it. This method has eight steps, and these eight links build a house of quality.

Part 5. What are the eight steps of QFD?

1. Identify customers

The most important customers are actually the people who buy the products. On the one hand, they will buy the product, on the other hand, they will tell other consumers about the quality or defects of the product, so they are also the so-called end consumers.

In addition, there are two types of consumers that we need to pay attention to, one is the manufacturer and the other is the seller. These two links are essential for the product we designed to go to the market and the final consumer. As far as the designer is concerned, so are the two. Therefore, in addition to the most important consumers, these two types of customers also need our attention.

Since QFD is still quite tall, let’s start with the basics. We are going to build a first-class house of quality for pencil design. Here, because it is a simple drawing of house of quality, I won’t subdivide all kinds of consumers.

2. Determine customer needs

Customer needs, that is, what customers want, is a crucial step. From the standpoint of customers, customers want products with long service life, easy maintenance, attractiveness and high scientific and technological content. On the other hand, customers are manufacturing customers. They want to be easy to produce (use available resources, do not transform the workshop for the production of products, introduce a large number of equipment, or increase too much energy for production, which is more troublesome), and use standard parts. There is also a group of customers, namely salespeople, who hope that the products can meet the requirements of customers and are easy to package, store, transport and so on.

3. Determine the relative importance of each demand

Evaluate the importance of each demand, give a weighted score, and then fill it in the house of quality. For so many needs, the larger the number, the higher the importance, according to the order from small to large. As an example of the house of quality, customers think that the importance of comfortable writing and strong decontamination ability of rubber is significantly greater than that of moderate price. Different customers may have different weights.

4. Identify and evaluate competitiveness: how to meet customer requirements at present

Especially from the perspective of competitors, what they have done to meet the needs of customers. Focus on the existing products, or the products of the enterprise, the manufacturer or the competitors. What functions have been realized in the current product, and where there are opportunities for improvement.

5. Production assignment: how to meet the needs of customers?

This step is crucial. On the basis of the first four steps, we have made a classified evaluation on these needs, and also made a classified evaluation on how the previous products meet these needs. Based on these conditions, the fifth step is very critical. Several indicators of product improvement (refill design, rubber decontamination, etc.) are proposed, and these indicators are quantifiable.

6. Relationship between customer needs in work assignment: how to determine customer needs?

Some people will say that the work assignment is based on the needs of customers, but even if it is based on the needs of customers, it depends on the relationship between it and the needs of customers. Their completion plays a decisive role in customer satisfaction. According to the weak, weak, general, close and very close relationship between the measures in the work assignment and customer needs, the relationship degree is expressed by 1, 3, 5, 7 and 9 respectively (between 2, 4, 6 and 8). These figures represent our work tasks. How relevant is it to customer needs.

7. Set work objectives

We have determined the improvement indicators in the work assignment and understood the relationship between various indicators and customer needs. Now what we need to do is actually to determine the value of each work goal to evaluate whether its function meets the needs of customers after product improvement. What about the degree of meeting the needs.

There are two initiatives:

1) See how competitors meet customer needs (combined with step 4)

2) Determine the indicators of new products

8. Determine the relationship between work needs

The last step is to complete the top of the quality tower. We have made quality improvement plans for various indicators, but is there any relationship between these indicators?

Relationships are basically divided into three types: positive correlation, negative correlation and uncorrelation.

Through the above eight steps, we not only translate the customer’s needs into our design requirements and process requirements, but also evaluate our transformation work.