Probabilistic analysis of the effect of resource constraints on system safety: Towing failures during the construction of concrete platforms

The failure of technical systems such as onshore platforms can generally be linked to some errors in design, construction or production, These errors, in turn, can often be related to features of the management or the organization. For example, time and budget constraints are unavoidable parts of industrial life, but the managers who set them are sometimes unaware of their actual implications. This is true because the technicians, operators and engineers that are subjected to these constraints generally try to satisfy them by taking shortcuts, sometimes without a clear idea of their long-term or short-term implications. Resource constraints thus have to be managed with care to avoid unanticipated catastrophic failures that can be the direct result of the shortcuts that people take to satisfy them. The objective of this study is to illustrate an analytical approach that allows improvement of the management of such constraints by anticipating their effects on the safety of marine systems. The framework is based on the SAM (system, actions, management) model that provides an analytical link between probabilistic risk analysis (PRA), human errors, and management and organizational factors. its focus is on concrete platforms and on the problems that might occur in the maritime operations of the construction process. We present first a simple probabilistic risk analysis framework for a concrete structure, We then examine the towing process during construction to identify the major potential errors corresponding to each variable of the PRA model. Finally, we link those human decisions and actions to management features involving schedule and budget constraints.