ATOS Analysis of Technical & Organisational Safety for major-accident prevention Risk analysis method integrating both technical and organisational factors and using safety performance indicators ---- J-C. LE COZE, F. PRATS, O. SALVI Institut National de l ’Environnement Industriel et des Risques Parc Technologique Alata, BP 2, F Verneuil-en-Halatte, France Phone: , fax: , Figure 1 Figure 2 Figure 3 1. The theoritical approach of ATOS 2. How to use the concept The context High complexity of organisations Difficulty to read through this complexity in order to foresee major accidents Need for a good safety climate/culture Need for a structured management system Need for indicators on the level of organisational efficiency for major accident prevention The following model describes how those constraints should be integrated in ATOS. First of all, the organisation is seen as the interaction of three elements. The technical (tools, equipment…), the system (act ivities, processes, procedures) and the people. The SMS is described as the structural aspect of the organisation, in other words, the treacability of the prevention system in place, called the FORMAL. The Human Factor is approached from the sociological angle, using a tool called “l’analyse stratégique” that aimed at assessing the organisation efficiency, integrating power plays and cultural aspects of the organisation. This represents the INFORMAL side of the organisation. Several types of organisations exist as described in figure 1. If we consider the positive assumption that various types of organisations can reach a high level of prevention efficiency, then we can represent them on a scale taking into account two parameters: 1. The quantity of INFORMAL activities happening everyday on site for the major accident prevention and the quantity of FORMAL activities described in the SMS. In the case of the European Directive SEVESO 2, the regulation imposes that the FORMAL side meet at least the SMS specifications described in the annexe 3 of the directive. The minimum balance is therefore to meet those specifications and to be able to demonstrate (paper focused) that the system exists and performs. 2. As the oil in an engine, the INFORMAL side must support the effective implementation and operability of the structure. If the oil is not appropriate, even with a good engine, the chance to reach high motor’s performance is low. It is the same with an appropriate oil used for a bad designed engine. Somehow, a balance is required between a good FORMAL activity (meeting the requirements of a good safety management system) and an INFORMAL activity (meeting the requirements of a sociological definition of the organisational efficiency) toward efficiency. The INFORMAL activity must be the effective support of a real working FORMAL structure. How could this be assessed? The aim of the ATOS methodology is to give a position of the organisation integrating those parameters defining the minimum balance as described in figure 2. The ATOS method is based on a concept of the organisation integrating the FORMAL and the INFORMAL sides. The FORMAL side is assessed through a classical audit approach of the management systems, a quality based approach, in order to evaluate the presence or not of the adequate structure. As shown in figure 3 the FORMAL aspect in our concern covers the SMS main chapters from the SEVESO 2 Directive. There are seven of them, from the organisation and personnel to the review of the system. The INFORMAL side, on the left of the figure 3, is assessed through a sociological approach, containing 7 chapters as well, defining the organisational parameters required for an efficient organisation. The idea of this figure is to show the fact that if both of the FORMAL and INFORMAL sides match, we can theoretically think that the organisation meets its prevention efficiency. The ATOS method is mainly concerned by the major hazard prevention. It means that it focuses only on the activities which give support to this prevention. It implies therefore an identification of those activities. Figure 4 shows a high view of the Major Hazard Prevention Activity. The inputs considered here are the one needed for the start of the ATOS methodology application. This is the information concerning the major hazards. Those information can be represented according to the Bow Tie approach figure 5. We need to know the potential scenario and the Line of Defence ( L.O.D) in place against the occurrence of the scenario from the initiating events to the consequences. Two alternatives are therefore possible: - trying to work on the causes of the initiating events which is quite a hard task as the experience do not allow us (fortunately) to find the whole organisational shortcomings creating the event condition, - or, better in that case, trying to work on the Line of Defence, and see how the organisation can assure the efficiency of them. Therefore, THE METHOD IS BASED ON THE DETERMINATION OF THE L.O.D IN ORDER TO IDENTIFY THE ORGANISATIONNAL ACTIVITIES REQUIRED FOR THE ASSURANCE OF THOSE BARRIERS. The outputs are the numbers of major accidents, the efficiency of the technical barriers or the number of initiating events if it is possible to identify them. The resources are actually what we describe above as being the organisation. At the bottom of the representation in figure 6 there is the risk control. The efficiency of the risk control is directly related to the resources above. Figure 6 is another proposed representation with the FORMAL and INFORMAL side. General organisational policies exist on the FORMAL side, at the higher level. There are here various main structural system policies like Quality, Environmental, Security of Information, Safety… The INFORMAL activity is composed by power plays, cultural aspects…directly related to human behaviour in an organisation. The figure 7 shows how the ATOS method is applied on this model. Figure 4 Figure 6 Figure 7 Figure 5 Figure 8 Figure 9Figure 10 Practically the analysis is operated as described in figure 9 and 10: - a classical technical risk analysis, - the identification of the activities required to be assured for the efficiency of the line of defence identified through the risk analysis. Once this is done the sociological tool is used in order to assess what truly happens, beyond what is written. The management structure is assessed through a quality based system audit. Conclusion At the moment, the concept is developed and we intend to implement it in the forthcoming months with industrialists, particularly SMEs. The figure 8 draw s the type of indicators which can be collected through the use of the method in order to build a score board fort he safety managers. The methodology indeed is foreseen to be transferable to the safety managers, according to the principles “you cannot manage if you cannot measure”.