Model and algorithm for computer-aided inventive problem analysis

Abstract

The paper presents the research activity developed by the authors in the field of computer-aided inventive problem solving: an original model and a dialogue-based software application have been developed by integrating the logic of ARIZ (Algorithm for the Inventive Problem Solving) with some OTSM-TRIZ (General Theory of Powerful Thinking) models in order to guide a user also with no TRIZ education to the analysis of inventive problems. The paper demonstrates that through a dialogue-based interaction it is possible to guide the user towards a proper formulation of the problem statement, which is an essential step of any conceptual design activity. The proposed software system, although still at a prototype stage, has been tested with students at Politecnico di Milano and at the University of Florence. The paper details the structure of the algorithm and the results of the first validation activity; then, it discusses about the possibility to integrate the proposed approach into a new generation of CAD systems.

Introduction

Nowadays companies all over the world consider the innovation of their products and their processes as the key to be competitive in the global market. In this context, the early stages of the design process gain the utmost importance since the impact of mistakes and poorly conceived design may lead to an unpredictable growth of costs during the development phase [1], [2], thus reducing the return of investment of the innovation itself.

Mostly during the last decade, new methods and tools have been introduced to enhance the innovation capability of the companies, more specifically by extending the boundaries of company’s knowledge, as well as by exploiting problem solving methods. However, the search for relevant knowledge from other domains with systematic and efficient processes implies a high investment of resources: technical experts should attend specific vocational seminars and courses to proficiently use those methods, leading to channeling money and time for this purpose. Downstream such investments and vocational experiences, valuable inventions constitute both the means and the goal in order to grant good perspectives for the corporate development.

However, at the same time, the need of the companies to reduce products’ time to market also causes a reduction of the time dedicated to product development cycles, thus implying a limitation in the expression of originality and inventiveness potential and, consequently, in the birth of valuable innovations. CAD/CAE systems’ development reflected substantially market tendencies; indeed, they have successfully met the exigencies of rapidly carrying out certain routine tasks, but they show a relevant gap in the stages where creativity and inventiveness of designers are of basilar importance [3]. Most of these systems let the users successfully carry out detailed design activities, but not enough efforts have been dedicated to the improvement of the conceptual design phase, e.g. tasks such as function analysis, concept generation and exploration [4]. The double goal of shortening the lead time and improving the efficiency of the product cycle thus results as a conflicting issue, which is not overcome by currently available CAD systems; new concepts are produced without a systematic approach and, indeed, such activity is typically referred as the fuzzy frontend of product innovation.

In the near future, computer-based systems are expected to reduce the investments and efforts currently needed to implement systematic innovation practices in the industrial environment. According to this perspective, the next evolutionary step of CAD/CAE systems must extend the support to the whole design process, from the inventive to the detailed design phase.

In order to properly define expectations and characteristics of the next generation of CAD systems, i.e. means capable to aid any kind of design activity, it is necessary to share a common perspective about what inventions and problems are and the role computers can play. Indeed, problem solving is an essential part of any design activity, traditionally characterized by a co-occurrence of tasks and problems to be addressed [5]: in fact, a design task can be divided into subtasks, some of which can reveal “difficult” problems to solve. The authors share Simon’s vision [6] about the importance to transform an “ill structured” problem into a “well structured problem” as an essential part of design. According to this perspective, modeling the “structure of a problem” is a key characteristic that the next generation of CAD systems should have; in other terms, computer-aided design should include computer-aided problem setting and problem solving.

In this context, Computer-Aided Innovation (CAI) systems constitute an emerging technology for assisting the conceptual design phase by supporting the analysis and the solution of inventive problems, but also improving the efficiency of any problem solving activity arising in an innovation process.

The authors’ research activity aims at defining a reference model and the main characteristics that a framework for Computer-Aided systems should have in order to solve technical problems whose solution cannot be achieved by means of routine design techniques. The first outcomes of this research activity have been presented in [7], with the introduction of a dialogue-based interface, capable to guide a designer in the analysis of a problematic task. In this paper the authors detail the algorithm underlying the proposed CAIPS system and demonstrate its potential and versatility through a series of tests with MS students in Mechanical Engineering at Politecnico di Milano and at the University of Florence. The proposed framework assumes that the overall requirements of the system have been already defined and the analysis is focused on the identification of the critical evaluation parameters related to the specific problem to be solved. Moreover, it helps to approach the problem with a structured process, that, during the analysis, narrows the design space towards the satisfaction of two plainly non-compatible requests and stimulates the user’s knowledge and his/her creative skills.

The authors claim that the here proposed original Computer-Aided Inventive Problem Solving (CAIPS) system is suitable for integration as a module of a Product Lifecycle Management (PLM) system, in agreement with the general trend of PLM to extend its domain to the earliest stages of product development. Such a CAIPS module aims at supporting the first steps of a design task, by highlighting the best directions of solution that can be further detailed through CAD/CAE system. Besides, any lack of performance or undesired behavior of a technical system emerging from CAE simulations can be analyzed with a structured approach through the CAIPS module, overcoming the barriers of psychological inertia thanks to the new perspectives highlighted by the proposed approach.

According to this goal, Section 2 illustrates a brief state of the art of problem classification and also describes problem solving approaches together with the main characteristics of related methods. This section also introduces TRIZ theory and related CAI tools. Section 3 presents the requirements and the proposed model for a TRIZ-Based CAIPS system suitable to be embedded into a PLM system that also overcomes the limitations of current tools. Then, the analysis module of the framework proposed by the authors is detailed in Section 4, while its application and testing are shown in Section 5. The conclusions built upon the discussed emerging remarks and the proposed future activities are drawn in the last section.