Defining criteria to characterise activity domains: refining Perrow's assumptions
Résumé
In 1984, Charles Perrow classified industrial domains according to their level of coupling and interactiveness (Perrow, 1984). More recently Hollnagel proposed to substitute the concept of interactiveness with the "manageability" dimension to emphasise that it is the consequence of complexity, rather than complexity itself that matters (Hollnagel, 2008). The classification of industrial domains is useful to understand which safety methods, among all available, are the most suitable to the typology of system they are applied to. Indeed, nowadays a lot of industries use actually only a few of the whole set of methods available (HSE, 2001). This paper aims at defining a set of criteria and a method to describe activity domains with respect to their level of coupling and manageability. The possibility to achieve a structured characterisation of domain activities will, in a later phase, permit the association of the appropriate safety assessment and accident investigation method to the respective domain. The paper will make use of a sample of safety experts to validate the choice of criteria and to update the original Perrow's matrix.