Chapter 23
Application of Causality Model
to Propose Maintenance Action of Parts
Takeru Nagahata, Hiroki Saitoh, and Hiroyuki Hiraoka
Abstract This paper discusses the application of a causality model to propose maintenance actions for the purpose of promoting the reuse of mechanical parts. To realize
effective reuse of mechanical parts for the development of a sustainable society, it is
essential to manage the individual parts over their entire life cycle. For this purpose,
we are developing a “part agent” that is programmed to follow its real-life counterpart throughout its life cycle. A part agent provides the user with appropriate advices
on the reuse of its part and promotes the circulation of reused parts. In this study, we
propose a method to estimate the probability of failure occurrence and determine the
corresponding maintenance action. The probability of the failure occurrence is calculated by the causality among events relating to the part and the conditional probability,
which is the probability of occurrence of the resultant event against the occurrence
of input events. To calculate the conditional probability of events representing the
state of a part, the deterioration of the part is simulated based on its operating and
environmental conditions. A causality model including this conditional probability
is constructed, and the failure probability of the part is estimated. In this paper, we
report a mechanism that updates the conditional probabilities according to the operating and environmental conditions that correspond to the different stages in a life
cycle.
Keywords Maintenance action · Causality model · Life cycle simulation · Part
agent · Conditional probability
23.1 Introduction
In recent years, the energy resources on the earth are being depleted, and the transition
from a consumption type society, which involves processes such as mass production,
mass consumption, and mass disposal, to a circulating society, which suppresses the
consumption of the resources, becomes urgent. To realize the circulating society, it is
T. Nagahata · H. Saitoh (B) · H. Hiraoka
Department of Precision Mechanics, Chuo University, Tokyo, Japan
e-mail: h-saitou@lcps.mech.chuo-u.ac.jp
© Springer Nature Singapore Pte Ltd. 2021
Y. Kishita et al. (eds.), EcoDesign and Sustainability I, Sustainable Production, Life Cycle
Engineering and Management, https://doi.org/10.1007/978-981-15-6779-7_23
325
Application of Causality Model
to Propose Maintenance Action of Parts
Takeru Nagahata, Hiroki Saitoh, and Hiroyuki Hiraoka
Abstract This paper discusses the application of a causality model to propose maintenance actions for the purpose of promoting the reuse of mechanical parts. To realize
effective reuse of mechanical parts for the development of a sustainable society, it is
essential to manage the individual parts over their entire life cycle. For this purpose,
we are developing a “part agent” that is programmed to follow its real-life counterpart throughout its life cycle. A part agent provides the user with appropriate advices
on the reuse of its part and promotes the circulation of reused parts. In this study, we
propose a method to estimate the probability of failure occurrence and determine the
corresponding maintenance action. The probability of the failure occurrence is calculated by the causality among events relating to the part and the conditional probability,
which is the probability of occurrence of the resultant event against the occurrence
of input events. To calculate the conditional probability of events representing the
state of a part, the deterioration of the part is simulated based on its operating and
environmental conditions. A causality model including this conditional probability
is constructed, and the failure probability of the part is estimated. In this paper, we
report a mechanism that updates the conditional probabilities according to the operating and environmental conditions that correspond to the different stages in a life
cycle.
Keywords Maintenance action · Causality model · Life cycle simulation · Part
agent · Conditional probability
23.1 Introduction
In recent years, the energy resources on the earth are being depleted, and the transition
from a consumption type society, which involves processes such as mass production,
mass consumption, and mass disposal, to a circulating society, which suppresses the
consumption of the resources, becomes urgent. To realize the circulating society, it is
T. Nagahata · H. Saitoh (B) · H. Hiraoka
Department of Precision Mechanics, Chuo University, Tokyo, Japan
e-mail: h-saitou@lcps.mech.chuo-u.ac.jp
© Springer Nature Singapore Pte Ltd. 2021
Y. Kishita et al. (eds.), EcoDesign and Sustainability I, Sustainable Production, Life Cycle
Engineering and Management, https://doi.org/10.1007/978-981-15-6779-7_23
325