New and Enhanced Features in Version 7

BlockSim 7 provides a sophisticated graphical interface to allow you to model the simplest or most complex systems using Reliability Block Diagrams (RBDs) or Fault Trees -- or a combination of both approaches! The software then algebraically computes exact system reliability results and optimum reliability allocations. BlockSim also provides a sophisticated discrete event simulation engine for reliability, maintainability, availability, throughput, life cycle cost summaries and related analyses. The following new and enhanced features in Version 7 allow you to perform analyses and simulations that are more powerful and realistic than ever!

Additional Distributions

In addition to the Weibull, mixed Weibull, normal, lognormal and exponential distributions, BlockSim 7 now supports the generalized gamma, gamma, logistic, loglogistic and Gumbel distributions. These additional distribution options provide even more modeling power and flexibility.

Phase Diagrams

You can use BlockSim’s intuitive new Phase Diagram Sheets to model systems that go through different phases during the course of their operation. For example, some aircraft components (such as landing gear) operate only during the take-off and landing phases of a mission and others (such as engines) experience a higher failure rate during these phases due to higher stress. Likewise, a manufacturing plant’s production may differ during the day shift and the night shift. To model this type of situation in BlockSim 7, simply create an RBD to describe the system’s operation during each phase and use the new Phase Diagram to describe how the system proceeds through the phases over time.

Exclusively in BlockSim, the Phase Diagram Sheets allow you to completely change the system configuration and component properties from one phase to another. In addition, you have the option to define Maintenance Phases to model scenarios in which a system goes into maintenance after completing a specific sequence of phases or skips remaining phases and goes directly to maintenance if a failure occurs. For example, if a failure occurs on an aircraft during taxiing, it may go directly to maintenance and then start from the beginning of the sequence after the repair (rather than from the point of failure as with traditional RBD analysis. This flexibility provides a tremendous leap forward in the ability to simulate more realistic situations.

More Realistic Simulation Factors

Duty Cycles: BlockSim 7 now allows you to apply a factor to define a duty cycle for a block that may experience a different stress load than the other blocks in the diagram. For example, when analyzing a computer system, the CD-ROM drive does not operate continuously. If you assume that the drive operates for 6 minutes out of every hour, for example, you could apply a Duty Cycle factor of 0.1 (10%). You can also treat the Duty Cycle as an acceleration factor in cases where it is necessary to increase or decrease the stress applied to a component. This option is also available for phases in Phase Diagrams, e.g. when the entire system goes through a different, more or less stressful environment.

Variable Throughput:
A systems throughput may vary over time. For example, the flow from an oil well may drop over time as the oil reserves are depleted or a manufacturing plant’s production may slowly ramp up again after shut-down. Version 7 provides a choice of three models to describe a system’s time-dependent variable throughput within your simulation.

Variable Throughput

Type I Restoration Factors: BlockSim 7 now provides more flexibility for using restoration factors to model imperfect maintenance scenarios. The software now supports the Kijima Type I model, which allows you to define maintenance that reduces a specified portion of the damage since the last repair only, along with the Kijima Type II model, where the maintenance is assumed to reduce a specified portion of the total damage to the item.

Additional Simulation Results

BlockSim 7's Simulation Results Explorer now reports a system's Mean Availability, Interval Mean Availability, System Failures and Throughput. For simulations performed on Phase Diagrams, results are reported at the system and phase levels, with a phase summary that includes Mean Duration, End-of-Phase Point Availability, Throughput, Executions and the Criticality Index for Aborted Missions.

Resource Usage Window

The new Resource Usage window provides an at-a-glance view of the diagrams and blocks where specific resources (e.g. maintenance policies, spare parts policies, etc.) are used within a project. This provides a quick summary of the project’s defined resources in either a list or tree view and also allows you to delete unused resources with a single click.

Resource Usage Window

Analytical FRED Reports

In addition to the simulation-based FRED reports for repairable systems, BlockSim 7 now provides an analytical report for non-repairable systems. This report provides a graphical representation of a non-repairable system’s reliability characteristics to help identify components that may require improvement.