Toward a decision-aiding framework for selecting alternative methods to lockout in machinery energy control: a literature-based approach
摘要
Lockout is the preferred method for controlling hazardous energy; however, it is not always effective during maintenance tasks that require partial energization. Other factors, such as productivity and technical constraints, may also prevent the use of lockout. In such cases, alternative methods are employed. The use of alternative methods has increased in recent years as technological advancements drive a shift from traditional approaches that disrupt business continuity toward solutions that maintain productivity while ensuring safety. Nevertheless, definitions, classifications, and validations of these methods remain inconsistent across industrial applications. Therefore, this paper reviews scientific publications and gray literature, including standards, regulations, and industrial practices, to examine how alternative methods are defined, applied, and validated. The analysis highlights significant gaps, including the lack of systematic, operational tools for selecting appropriate methods. To address these issues, the study proposes three main contributions: a new task-based decision-support tool, a nine-group mechanism-based categorization of alternative methods, and a task–method compatibility matrix to facilitate informed decision-making. These tools were developed by synthesizing the results of the literature review and strengthened with expert input and a cross-analysis of international standards and regulations. Collectively, they provide a structured foundation for decision-making and aim to align industrial practices with regulatory requirements. Finally, to examine the consistency of the proposed framework, it was illustrated through comparative applications in industrial cases. This work lays the foundation for future research, emphasizing the importance of expert and practical validation to refine the proposed frameworks and advance alternative methods into reliable safety strategies.