GRIF | BStoK - Evaluating the performance of dynamic systems with stochastic block diagrams

Stochastic block diagrams are created via the intuitive graphical interface. All the elements (input, block, link, output) needed to build the required model can be created in just a few clicks. Each block can then be configured according to its failures, repairs, start/stop condition, maintenance schedule, etc.

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

Once the block diagram is created, the following features are available on BStoK:

• Availability, reliability and performance calculations for each block and system.
• Customized calculations with additional observed variables.
• Spare part and maintenance team management.
• Incident duration analysis.
• List of main contributors to downtime.

The module uses the MOCA-RP calculation engine which quickly produces the anticipated results and provides information on the confidence level attributed to them.

Groups and sub-systems: this notion of hierarchy means that the model can be divided up according to the actual distribution of the system whatever the number of inputs/outputs. A preview is displayed on the block so that its composition is always visible.  

Readability: the block diagram approach provides the user with a graphic representation of the architecture of the system being analyzed. No previous Petri Net knowledge is required to use this module.

Model construction time: a model comprises just three different element types: blocks, connectors, and links. The user selects the characteristics for each block or system element from a configuration interface. Data tables can be used to modify one characteristic on several blocks at the same time.

Interdependency between blocks: the BStoK module allows for interaction between different blocks, whether common cause failures, redundancies, or failures on shared resources (repairs, spare parts, etc.).

Compatibility with Petro: models from BStoK can be used in the Petro module to perform calculations on processing flow.

Computation speed: this module features a computation simulator (Moca-RP) which rapidly produces the required results and provides information on the level of confidence attributed to them.

Multi-core computing: as with all the modules in the simulation package, calculations can be performed on several processors simultaneously which significantly reduces calculation time. A high-performance computing plug-in is also available for use with supercomputers.

Interactive simulation: users can validate the model’s operation using step-by-step simulation, as with the Petri and Petro modules.

Summary of results. All the key results are summarized in a separate window:

• Mean production and production over a number of years,
• Incidents,
• Main contributors,
• Use of spare parts and the maintenance team.

• 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.
• BStoK can read RBDs from the BFiab module.
• A summary of results is displayed in a separate window showing all the relevant results.

• Petri module: you can open and save a BStoK model in the Petri module. The prototypes created can then be integrated into a model and then used by engineers who are not Petri net specialists.
• BFiab module: you can import reliability diagram blocks already created with BFiab and to which you would like to add dependencies between blocks.
• Petro module: models from BStoK can be used in the Petro module to perform specific calculations for flow processing.