1st ICAI 2020

International Conference on Automotive Industry 2020

Mladá Boleslav, Czech Republic

concept is based on the multimethod simulation approach, which includes three major methodologies used to build dynamic simulation models for the complex, large-scale systems: System Dynamics Modelling, Discrete Event Modelling and Agent Based Modelling. The model is dynamic and takes into account the possible disruptive events, e.g. disruption in supply process and unforeseen changes in demand. Implementation of the model has been made on the example of steel mills, whose logistics system is global. Simulation studies on this model were designed to evaluate the vulnerability of the whole logistics system to disturbances occurring in both its parts. As a measure of vulnerability we have taken into account an ordered pair (duplet): the expected loss of performance (L D ), and disruption time (T D ). 2. Problem Formulation and Methodology Although the ideas of vulnerability and resilience were introduced relatively recently, they have already been examined in many serious studies, both theoretical and practical, in the area of engineered systems (e.g. AMBER 2009, Kroger & Zio 2011, Sheffi 2007). Also in the area of logistics and supply chains a significant number of interesting works has been published (e.g. Kleindorfer & Saad 2005, Peck 2006, Waters 2007). The common denominator of these works can be, in our opinion, a process continuity oriented approach. This approach has been the subject of several our works (e.g. Bukowski, Feliks & Majewska 2015 and 2016, Bukowski 2019), in which we proposed the following basic definitions of the main terms: • Continuity – a system capability to deliver products or services at acceptable, predefined performance level under the real work conditions (e.g. despite disruptive events DE ). • Disruptive event (DE) – an act of delaying or interrupting the process continuity (e.g. system failure, natural catastrophe, man-made fault). • Vulnerability to a disruptive event (V) – the degree to which a system is affected by a disruptive event. • Vulnerability metric – the disruption impact described by two main indicators: the expected loss of performance (L D ) , and disruption time (T D ) . • Resilience to a disruptive event (RES) – the ability of a system to absorb and withstand the disruption impact, and still continue to deliver products or services at acceptable predefined performance level, as well as the adapt- capacity to a new work conditions. • Resilience metric – a collective term described by the three main indicators: absorbability (ABS) , recoverability (REC) , and adaptability (ADA) . Based on these assumptions we proposed the concept of disruption tolerant operation (Bukowski 2019). This concept is based on the process oriented approach and is closely related to the ideas of resilient enterprise as well as business continuity management. The model is based on a typical course of a service delivery process, interrupted by an occurrence of a disruptive event leading to a disruption of this process continuity. A quantitative interpretation of this model is shown in Figure 1. The thick line shows the course of an idealized system operation as it changes its performance in function of time. Prior to the occurrence of a disruptive event the system was functioning

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