GRIF | Flex – Evaluating the performances of dynamic systems using MBSA based on Petri Nets

Flex is a model-based Safety Assessment tool used to create blocks/components (or select them from a library) and link them together.
Components are blocks with several connection interfaces and their behavior is defined using Stochastic Petri Nets with predicates. The versatility of Petri Nets and the MOCA-RP language is a major advantage when creating components, in order to protect and assign transitions. The components can be configured and used, even by those who are not familiar with Petri Nets but understand how components interact with one other. Once the components have been stored in the library, users can create a system model by assembling the components.

Once the system model has been created, Flex runs a Monte Carlo Simulation to provide the following results:  

• Component failure (counting, duration).
• System shutdown duration analysis.
• Use of maintenance teams and spare parts consumption.
• Sequences or cut sets leading to a specific event.

• Modelling power: Petri Net experts can use the Petri module, the benchmark software application for Stochastic Petri Nets, to create components. The major advantage of stochastic Petri nets is their capacity for modeling and for describing the dysfunctional (component failures) and functional (architecture and support functions such as maintenance or reconfiguration procedures) parts of a system.
• Step-by-step interactive simulation:  The Flex module includes a step-by-step simulator, a key feature for checking/validating models. It also ensures the modeling is accurate before running computations. The simulator can also be used to explain system behavior and is a good training tool for helping people understand how it works.
• Scope : whether modeling an assembly line, an electrical grid, a production system or any other type of system, this module is suited to all industrial sectors. Users can always create additional variables to assess and therefore can obtain results concerning every aspect of their system. Consequently, Flex has other uses such as safety considerations, performance assessments and SIL optimization.
• Reusable libraries: once a library has been created for an initial analysis, it can be reused for other systems comprising the same kinds of components, without requiring the presence of a Petri-Net expert. This makes it easier for companies to capitalize on the results of past analyses.
• Hierarchical systems: complex systems that cannot be described on a single page can be broken down into several sub-systems that may or may not be interconnected.

• Option to automate calculations (batch runs) and draw variations for sensitivity analysis.
• Results are stored in the document and can be exported in a variety of formats (csv, XML, Excel, etc.).
• Results can be viewed as line graphs, pie charts or histograms.
• Printing in PDF vector format produces high-quality images and the files are small enough to be sent by email, even if the document contains hundreds of pages.
• Interaction with the operating system: option to copy/paste either to or from word processing software, spreadsheets, or presentation tools.
• With the “Attribute” feature (system with custom properties), you can add any information you require to each object in the document, either to provide a more precise description or for traceability or result grouping purposes.