Safety management : A multi-level control problem

• Activities in safety management build on a control metaphor by which control loops are built into the man, technology, organisational and information (MTOI) systems to ensure a continued safety of the operated systems. In this paper we take a closer look on concepts of control theory to investigate their relationships with safety management. We argue that successful control relies on four necessary conditions, i.e. a system model, observability, controllability and a preference function. The control metaphor suggests a division of the state space of the modelled system into regions of safe and unsafe states. Models created for selected subsystems of the MTOI-system provide a focus for control design and safety assessments. Limitations in predicting system response place impediments to risk assessments, which suggest that new complementary approaches would be needed. We propose that polycentric control may provide a concept to consider in a search for a path forward. We investigate approaches for modelling management systems and safety management. In spite of promises in the use of a control metaphor for safety management there are still dilemmas that have to be solved case by case. As a conclusion we argue that the control metaphor provides useful insights in suggesting requirements on and designs of safety management systems. The paper draws on experience from the Vattenfall Safety Management Institute (SMI), which started its operation in 2006.

Nyckelord

Safety management

Control structures

Modelling safety

Methods and tools

Nuclear power

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)