## 3 Methodology
### Introduction to DCOR Processes
#### 3.3.2 Level 2 of the DCOR Model  
The design chain process has different definitions due to product revision, NPD or new fabrication design, and R&D in the DCOR model. Level 2 of the DCOR model is then consequently selected and extended from the design chain domain of Level 1. By extending Level 1 to Level 2 of the DCOR model, this research further discusses and studies of the D1 process in the design chain elements in detail because the major function of the case company is R&D.  
In the DCOR model, the R&D of the PCB for testing is part of the NPD process, which is therefore the method of deriving Level 2 of the DCOR model in this research. Level 2 of the DCOR model must confine and verify the domain of the design chain definition as well as judge the research direction of the design chain to see if it is a revision, NPD, or new fabrication R&D from the three design projects of development, design, and integration.  
Figure 1: Flowchart of PCB R&D process across the case company’s design chain.  
The main topic of the DCOR model study in this research is the R&D of a new PCB product in the case company. Because the case company's PCB design is specialized for high-end product testing, the PCB design processes have to verify design graphs, specifications, and engineering problems with customers and design companies multiple times to ensure that the design concept and quality match the signal frequencies, impedances, and speeds of IC products that the customer needs to test. However, communication processes result in long waiting times when verifying the solutions of engineering problems and delay the R&D process; therefore, this research analyzes the design chain items using definitions of Level 2 of the DCOR model to improve it.  
The case company's R&D department focuses mainly on planning the integration project of the design chain and new product design, evaluating and verifying the design data viable for fabrication, and then collaborating with the design company to start new product projects. After new product testing, if there are problems from IC testing due to bad design or changes in the customer's testing needs that results in the need for revision or improvement of the original design, the customer will notify the case company to prepare and carry out design revision with the collaboration of the design company.  
As the case company dominates the new product design project, the plan and design need to include plan design chain (PDC), plan design (PD), plan research (PR), plan integrate (PI), and plan amend (PA). On the other hand, the design process covers design concept (DC), design detail (DD), and design review (DR). The case company's new product projects are independent. Although the new products may share the same type, they usually have different functions and circuit connections. Therefore, this research classified the case company as Level 2 of the DCOR model: R2 (Research New Product), I2 (Integrate New Product), and A2 (Amend Deficient Product).  
Figure 3: Level 1 of the DCOR model of the PCB R&D processes.  
Figure 2: Level 1 of the DCOR model.  
The design company communicates and discusses with the case company about the relevant design and engineering problems, such as concepts, details, and verification of design, and then provides their internal corresponding project to be verified by the case company. Therefore, in Level 2 of the DCOR model in Figure 4, the design company has Plan: PP, PR, PD, PI, and PA, and Design: DC, DD, and DR.