**3. Conclusions**

The aim of this study was to present the framework for making maintenance decisions for mechanical equipment to improve their reliability and security and to decrease safety accidents and economic losses. The framework adopts the idea of different equipment classifications based on their own risk level with different MDMETs. We summarized 10 evaluation indexes for evaluating the risk level of the mechanical equipment and defined a set of scoring criteria to quantify the subjective evaluation in the petrochemical industry. The evaluation model of the risk level was established based on the AHP and the MCS, which calculate the weight of the evaluation indexes and remove the subjective effects in the scoring process. Moreover, we divided the mechanical equipment into three categories based on their risk level and established their MDMETs.

From the discussion above, we can conclude that the framework for making maintenance decisions, combining the quantitative and qualitative methods with the mathematical model and decision-making theory, can be effectively applied to mechanical equipment and provides them with reasonable and scientific maintenance strategies. The framework is suitable not only for mechanical equipment but also for other similar equipment on the premise that the evaluation index and scoring criteria are revised based on their respective features. This framework also includes three analysis methods for the risk level of the mechanical equipment, which can be put into use for other equipment or systems to filter out the unimportant parts. Moreover, the analyzed methods and results in this study will help the study of asset integrity management (AIM) in oil companies.

**Author details**

China

**343**

Yang Tang\*, Xin Yang and Guorong Wang

*Maintenance Decision Method Based on Risk Level DOI: http://dx.doi.org/10.5772/intechopen.91913*

provided the original work is properly cited.

\*Address all correspondence to: tangyanggreat@126.com

School of Mechatronic Engineering, Southwest Petroleum University, Chengdu,

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

*Maintenance Decision Method Based on Risk Level DOI: http://dx.doi.org/10.5772/intechopen.91913*
