How to Prevent Unauthorized Persons
from Entering the Auto-locking Door of Apartment Building:
Applying TRIZ/USIT to A Social & Technical Problem
Toru Nakagawa and Arata Fujita (Osaka Gakuin University)
Abstract
For securing the entrance of residential apartment buildings, the auto-locking door system is typically installed. Visitors without authorized keys have to communicate with the residents through the (video-)interphone to get the door unlocked. In reality, however, unauthorized persons can easily pass through the entrance door, simply by behaving just like a resident and following other residents. This problem is relevant more to psychology and social behavior of people than to technology. In the present case study, we analyzed the problem by using standard methods of TRIZ/USIT, represented the cause-effect relationship in the RCA+ method to find root contradictions, and generated various solutions. The solutions involve not only technical but also psychological and sociological aspects. The present study has demonstrated that TRIZ/USIT can be applied smoothly and effectively to non-technological problems.
Extended Abstract
The present paper is based on the thesis work of A. Fujita [1] in Faculty of Informatics of Osaka Gakuin University and further research by T. Nakagawa, carried out with the aim of applying TRIZ/USIT to creative problem solving of an everyday-life problem.
For analyzing the problem, the analysis of space characteristics and the analysis of time characteristics were carried out. The problem was further analyzed by considering various ways of passing through the auto-locking door without authentication from the standpoint of the unauthorized person (subversion analysis). This clarifies the fact that unauthorized persons can enter the door easily and smoothly by choosing the timing when the auto-locking door is kept open.
Reasons for such weak points in the system were discussed in the thesis group. All the observations discussed are grouped and rearranged in the scheme close to the RCA+ Diagram proposed by Valery Souchkov, especially for revealing the Cause-Effects relationships. As the result, the root causes of the problem and the root contradictions which have been prohibited appropriate solutions so far have been revealed.
For solving such contradictions, we have applied TRIZ/USIT thinking methods and have generated several directions of solutions. The outline of the solution directions are briefly summarized in the following:
(a) The existing auto-locking door is typically kept open for about 10 seconds. ==> For making the response quicker after the passing by the resident, small parts of the door are closed, or else any violation is detected with a sensor and noticed/alarmed by the system.
(b) At present it is often found that residents allow unauthorized persons to enter. ==> The principle that unauthorized persons are not allowed to enter should be enforced more among the residents. Residents are requested to tell to the System the number of company who are going to enter at every moment of opening the door.
(c) In the existing systems, the rule of action is not effective (or not clearly stated) in the cases when two groups happen to meet in front of the door and want to enter the door. ==> Enforce the rule of getting authentication individually for each group. Each group should tell to the System the number of people in the group.
The overall structure of the problem is illustrated in the following figure, which contains the description of current methods, causes of the problem, and directions to solution [1].
A clear set of solutions of a new IT control system is proposed in the paper.
Presenter's Profile: Toru Nakagawa
Professor of Informatics at Osaka Gakuin University. Since he was first exposed to TRIZ in May 1997, he endeavored to introduce it into Fujitsu Labs for which he was working. After moving to the University in April 1998, he has been working for introducing TRIZ into Japanese industries and academia. In November 1998 he founded the public WWW site "TRIZ Home Page in Japan" and serves as the Editor. He is currently working to present TRIZ in a simple, unified and yet powerful way for solving real industrial problems and for teaching students. He has been serving as the Program Chairperson of TRIZ Symposium in Japan, 2005 - 2007. -- In his carrier, he was a researcher in physical chemistry in a university, then was a researcher and managing staff in information science in an industry laboratory. -- E-mail: