Development of the step complexity measure for emergency operating procedures using entropy concepts

Citation
Jy. Park et al., Development of the step complexity measure for emergency operating procedures using entropy concepts, RELIAB ENG, 71(2), 2001, pp. 115-130
Citations number
56
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Engineering Management /General
Journal title
RELIABILITY ENGINEERING & SYSTEM SAFETY
ISSN journal
0951-8320 → ACNP
Volume
71
Issue
2
Year of publication
2001
Pages
115 - 130
Database
ISI
SICI code
0951-8320(200102)71:2<115:DOTSCM>2.0.ZU;2-A
Abstract
For a nuclear power plant (NPP), symptom-based emergency operating procedur es (EOPs) have been adopted to enhance the safety of NPPs through reduction of operators' workload under emergency conditions. Symptom-based EOPs, how ever, could place a workload on operators because they have to not only ide ntify related symptoms, but also understand the context of steps that shoul d be carried out. Therefore, many qualitative checklists are suggested to e nsure the appropriateness of steps included in EOPs. However, since these q ualitative evaluations have some drawbacks, a quantitative measure that can roughly estimate the complexity of EOP steps is imperative to compensate f or them. In this paper, a method to evaluate the complexity of an EOP step is develo ped based on entropy measures that have been used in software engineering. Based on these, step complexity (SC) measure that can evaluate SC from vari ous viewpoints (such as the amount of information/operators' actions includ ed in each EOP step, and the logic structure of each EOP step) was develope d. To verify the suitableness of the SC measure, estimated SC values are compa red with subjective task load scores obtained from the NASA-TLX (task load index) method and step performance time obtained from a full scope simulato r. From these comparisons, it was observed that estimated SC values general ly agree with the NASA-TLX scores and step performance time data. Thus, it could be concluded that the developed SC measure would be considered for ev aluating SC of an EOP step. (C) 2001 Published by Elsevier Science Ltd.