## 4 Results and Discussions
### Analysis Steps
#### 4.1.2 Improvement Step  
The case company gathers engineers from all departments to brainstorm on ideas to improve the five major problems from the cause-and-effect chart diagnosed by the DCOR model. The outcomes can be summarized in the following eight solutions:  
1. The case company should build up a database for long-term customers' new product projects to store their new product signals and conventional materials. When customers start discussions about new product needs, the stored data will remind the customers about materials used in the previous product designs and compare the differences between the new products and the previous ones, thereby efficiently reducing the waiting and verification time from repeatedly asking the customers about the same engineering questions. Figure 7: Cause-and-effect chart of the PCB R&D process. Both the case company and the design company should have their own database to ensure rapid evolving fabrication capability and customer requests as well as decrease the numbers and time of repeated engineering question inquiries. Therefore, they can reveal design data problems and issues needing further reviews and verifications of new products, thereby improving the problems of design process interruptions stemming from engineering mishaps. 3. After the individual databases of the case company and the design company are built up, not many engineers are needed for repeating engineering problem verifications. Engineering problems can be referred to the previous product design data, examined, and responded to by accessing the databases. Designers just need to look up and follow the related examined engineering problems for new designs monitored and verified by a senior engineer during the design process. The goal is to shorten the delivery time, decrease mistake rates, and conserve manpower. 4. The design company follows the models in the database to design and set up specific stages with corresponding inspection items instead of random inspection stages of design schematic files for the case company. Such a method of conducting inspections at fixed stages can reduce the mistake rates of file checking as well as the inspection time, numbers, and error risks of the case company. 5. The case company communicates and discusses potential future revisions of some IC signals and some IC program design with the customer, which is treated exceptionally. After the PCB design is over, it takes less time and fewer efforts to modify the PCB design because of IC program revisions. 6. The case company inquiries about the customer's ideal PCB design and it notes the corresponding attention in the database before a project. The case company then verifies with the customer each detailed design element and regulation to determine the design goal before starting the design and decreases the scale of revision if the finished design does not fit the customer's expectation. 7. A senior designer should participate in a new R&D project if possible so that he or she can pass his or her experience from customer's preferences and ideal design styles to newcomers. In this way, it decreases design errors resulting in quality issues caused by new designers with a lack of experience. 8. The senior designers are asked to create files of checking lists or attention memorandums of design processes for newcomers or designers who never come into contact with certain customers before having design references. During each design process, every designer must fill new customer requests or new special specifications back into these files as references for other designers in future design projects. The delivery time was shortened by 10 days, from the original 92 days to 82 days, with the cooperation and efforts by the customer, the case company, and the design company. In Figure 8, the case company abbreviated many stages of verifications and inspections by using the aforementioned improvement methods.