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Author: Yung-Chieh Hung (2007-07-12); recommendation: Yeh-Liang Hsu (2007-07-12).
Note: This article is Chapter 7 of Yung-Chieh Hung’s PhD thesis “Development of an Innovative Patent-based Design Methodology.”

Chapter 7. Conclusions and discussions

7.1 Conclusions

Systematic product design processes commonly seen in research literature or design textbooks often start from need finding, specification development, conceptual design, detail design, to production. However, the design problems constantly faced by engineering designers in industries is how to design around existing patents, which requires a completely different design approach and knowledge. This type of design problem is often a local innovation of an existing patent. The rules of patent infringement judgment present the major constraints to such design problems, and designers may have to sacrifice the performance of the product in order not to infringe on existing patents.

This research proposes a patent-based design process by systematically integrating patent information, the rules of patent infringement judgment, strategies of designing around patents, and the innovation design methodology. The basic idea of the process is to generate a new design concept that is a slight variation of one of the concerned patents but does not infringe with the existing patent.

Figure 7-1 shows the flowchart of this patent-based design process. To start with, the designer identifies the related patents to be designed around and to collect functions and core techniques of each related patent, as in standard patent analysis. After patent search and screening, the patents that achieve the same functions are selected to be designed around. Each patent is then symbolized by a “design matrix” converted from the design parameters (DPs) and functional requirements (FRs) of the patent. The design matrices of the patents can be manipulated mathematically.

Figure 7-2 shows the detailed flow chart of the design around algorithm. After transferring the related patents into design matrices, the designer assigns priorities of DPs to be designed around. There are 3 rules in assigning priority: (1) In multiple patents, the DPs appear in fewest patents have highest priority. (2) For DPs appearing in the same patent, the priority of DPs to be designed around is given to those having the least contribution to the FRs, and (3) the DPs having minimal interaction with other DPs. Then the columns and rows of design matrix are sorted according to the number of non-zero elements.

After the priorities of DPs are decided, the “design around operation matrices” are applied to the design matrix to generate a new design matrix which is similar to but does not infringe with the design matrix of the patent to be designed around. In this research, four design around operation matrices are proposed. They are elimination, replacement, integration and decomposition. Note that the design around operation matrices will first be applied to the DPs which were assigned highest priority to be designed around. After operating the design around process, new design matrices that do not infringe with the existing patents and the corresponding design problems are generated.

Based on this existing patent, TRIZ is used to transform the new design matrix back into a real engineering design. However, this transformation may fail because there may not be a feasible design corresponding to the new design matrix generated by the algorithm. If TRIZ fails to generate a feasible design, the algorithm is triggered again to apply the design around operation matrix to the DPs which were assigned the 2nd highest priority. The process continues until finally a new design concept is generated.

Figure 7-1. Flowchart of the patent-based design process

Figure 7-2. Detail flowchart of the design around algorithm

7.2 Discussions

The patent-based design process developed in this research aims to assist enterprises to enhance the efficiency of product development, lower the possibility of patent infringements, and increase the patentability of results of innovation. The possible future development of this research is outlined as follows::

(1)    The innovation design method based on design-around approach can be further computerized. Referring to Figure 7-1, stage 1 (patent analysis) and the stage 4 (TRIZ) depends on the designer’s domain knowledge and are performed manually. Stage 2 (design representation) and the stage 3 (design around algorithm) are standard algorithmic process and can be computerized.

(2)    More application examples should be tried out to fine tune the detailed steps of this process.

(3)    While TRIZ’s “contradiction table” is a perfect match with this process, other innovative design methods should also used here to increase the degree of innovation.