BStoK Module

To evaluate the performance of dynamic systems using

Stochastic block diagrams

BStoK is used to model systems as stochastic block diagrams. Unlike reliability block diagrams, BStoK integrates the dynamic behavior of systems.

The module uses the computation engine Moca-RP (for Monte-Carlo – Réseaux de Petri (Petri Networks)), owned by Total and, as its name suggests, based on the Monte-Carlo simulation which enables the exhaustive recovery of all the information on the model. Moca-RP has a dual advantage in that it generates accurate results without compromising calculation speed and this makes it one of the most high-performance calculation engines on the market

Modeling and computations

Stochastic block diagrams are created using an intuitive graphical interface. All the elements (input, block, link, output) required to build the desired model can be created in just a few clicks.

When a block is created, a Petri net is automatically generated. This background use of Petri nets means that the BStoK module has a large library of block configurations and models the interactions between the different system elements.

Once the blocks, links and connectors have been created, the Moca-RP calculation engine provides the following functionalities:

  • Observation of unavailability, reliability and performance in each modeled block;
  • Customized creation and selection of the variables to be calculated;
  • Calculation at a given time or over a time interval for each indicator or variable observed (value at t, average value between 0 and t, the first value assigned, etc.).

Specificities and strengths

Readability :

The block diagram approach gives the user a graphic representation of the architecture of the system studied. No previous knowledge of modeling using Petri networks is necessary to use this module.

Model construction time:

A model comprises just three different types of elements: blocks, connectors and links. The user selects the characteristics for each block or system element from a configuration interface. The data tables can be used to rapidly modify one characteristic simultaneously on several blocks.

Groups and sub-systems

In addition to the pages that enable you to organize your diagram and make it easier to print, this module enables you to create systems which in turn comprise sub-systems. This notion of hierarchy means that the model can be divided up according to the actual deconstruction of the system. You can add or remove as many inputs/outputs as you want. A preview of the sub-system always appears on the block so that its composition can be seen at all times.

Interdependence between blocks:

The BStoK module incorporates the interactions among the different blocks, whether common cause failures, redundancies or failures on shared resources (repairer, spare parts, etc.).

Compatibility with Petri, Petro, BFiab:

BStoK models can be saved and opened in the Petri module. Prototypes created in the Petri module can be integrated into a model and then used by engineers who are not Petri network specialists. Reliability block diagrams created by BFiab can be imported to add dependencies among blocks. Finally, models from BStoK can be used in the Petro module to run calculations specific to processing flow.

Calculation speed:

The module includes a calculation simulator (Moca-RP) which rapidly generates the desired results and provides information on the level of confidence attributable to them.

Interactive simulation:

The 2015 version validates the model operation step by step, as in the Petri and Petro modules.

Data exploitation and results

  • Synthesis of input data in the form of tables that makes it easier to control the quality of an entry.
  • Possibility of automating calculations (batch run).
  • Results stored in the same document and exportable in different formats (csv, XML, Excel, etc.).
  • Visualization of results as curves, pie charts or histograms.
  • Vector printing of graphic elements and curves in PDF format which maintains optimum quality, even in A3 or A2 format.
  • Interaction with the operating system: option to copy/paste curves or results to word processing software, spreadsheets or presentation tools.
  • Possible connection to MySQL, Access and Excel databases to recover the values to be used for the settings.

Multi-CPU Calculation:

As in all the modules of the simulation package, calculations can be run simultaneously on several processors, to radically reduce calculation time.

GRaphical Interface for reliability Forecasting