ReliaSoft BlockSim

A comprehensive platform for system reliability, availability, maintainability and related analyses

System Reliability, Availability, Maintainability and Related Analyses

ReliaSoft Blocksim is a powerful yet intuitive dedicated system enabling you to model the simplest or most complex systems and processes using reliability block diagrams (RBDs), fault tree analysis (FTA) and Markov diagrams.

Using exact computations or discrete event simulation, BlockSim facilitates a wide variety of analyses required by product designers and asset managers for both repairable and non-repairable systems. This includes reliability analysis, maintainability analysis, availability analysis, reliability optimization, throughput calculation, resource allocation, life cycle cost estimation and other system analyses.

BlockSim can also be extended to include Process Flow and Event Analysis (RENO).

Why Use ReliaSoft BlockSim?

  • Assess system reliability and lower the failure rates

    Quickly build complex models to identify potential areas of poor reliability and where improvements can be made. Identify critical components (or failure modes).

  • Make predictions and recognize the patterns

    Model the behavior of a system with Markov diagrams, and analyze partial or degraded working states.

  • Obtain estimated performance metrics that can facilitate decision-making

    Applications include scheduling planned maintenance, planning for spares, identifying bottlenecks in production throughput and estimating life cycle costs.

  • Find the most effective ways to improve system performance

    Design any configuration to analyze its reliability, maintainability, and availability using load sharing, standby redundancy, phases, and duty cycles to represent the system.

  • Estimate production capacity and identify critical components

    Identify bottlenecks in production, optimize resource allocation, and improve the processing efficiency of any system with throughput analysis.

  • Enhance your maintenance optimization and simulation modeling

    Model the reliability and maintainability of equipment and analyze multiple flow types within the system using process flow diagrams.

  • Make crucial decisions easier with life cycle cost analysis

    Specify the direct and indirect costs associated with the maintenance strategies that you have defined, including costs related to downtime, maintenance crews, spares, etc.

  • Model any configuration

    Analyze its reliability, maintainability and availability using load sharing, standby redundancy, phases and duty cycles to represent the system.

Introducing ReliaSoft 2022

ReliaSoft 2022 is designed to make your reliability analyses more effective and improve your productivity with streamlined user experience. Enhancements include a new Fault Tree Analyses calculation method within ReliaSoft BlockSim for more complete and accurate cut sets and better results for larger FTAs.

Cost Modelling using ReliaSoft Blocksim

Cost modelling is a method of estimating the costs associated with a project or product. As with any estimation process, it is important to capture the variability of inputs and to report on the sensitivity of the outputs to this variation.

We look at how a systems modelling tool like ReliaSoft BlockSim can be used to model costs associated with an asset or product.


Reliability Block Diagrams (RBDs)

Easy drag-and-drop techniques allow you to build reliability block diagrams (RBDs) for the simplest to the most complex systems.

  • Simple Series and Parallel: Simple series configuration assumes that the failure of any one component causes the system to fail, while simple parallel configuration assumes full redundancy in the system.
  • Complex: Require a more advanced analytical treatment than a simple combination of series and parallel blocks. Such configurations may be required for analyzing network systems, competing failure modes, etc.
  • k-out-of-n: Node blocks can be used to define k-out-of-n redundancy, where a specified number of paths leading to the node must succeed in order for the system to succeed.
  • Load Sharing: Each block supports a percentage of the total load. BlockSim supports stress-independent distributions for load sharing blocks.
  • Standby Redundancy: Standby blocks are available to become active under specified circumstances. BlockSim can model hot, warm or cold standby configurations.
  • Mirrored Blocks: Allow you to put the exact same component in more than one location within the diagram. These blocks can be used, for example, to simulate bi-directional paths in a communications network. BlockSim offers increased modeling flexibility by supporting mirrors across different diagrams.
  • Multi Blocks: Help you to save time (and space in the diagram) by using a single block to represent multiple identical components configured in series or parallel.
  • Subdiagrams: BlockSim offers a virtually unlimited capability to link diagrams as components in other diagrams, which provides a variety of opportunities to encapsulate one analysis into another.
Fault Tree Analysis

Supports all of the traditional gates and event symbols that are applicable to system reliability and related analyses, with additional logic gates that represent load sharing and standby redundancy configurations

Fault tree diagrams can be configured to display intermediate results at each individual gate. Your BlockSim projects can contain both fault trees and reliability block diagrams together in the same analysis workspace. You can also integrate your fault trees and RBDs by linking a fault tree as a subdiagram to an RBD or vice versa, copying events from a fault tree diagram and pasting them as blocks in an RBD, and automatically converting any fault tree to an RBD.

The available event symbols include Basic, Undeveloped, Trigger, Resultant and Conditional, while the supported fault tree diagram gates include:

  • AND and OR gates
  • NOT, NAND and NOR gates
  • Voting gates
  • Inhibit gates
  • Priority AND and Sequence Enforcing gates
  • Load Sharing and Standby gates
Markov Diagrams

Model the behavior of a system in various states using a memoryless process, where the next state of the system is only dependent on the transition values and the current state of the system

This gives you the ability to look at partial or degraded working states, and to start analysis in varying states. If you have the Event Analysis module you can also analyze a Markov diagram during a simulation and use the analysis result in your flowchart.

Reliability Analysis via Analytical Diagrams

Comprehensive system reliability metrics and plots

You can use the convenient Quick Calculation Pad (QCP) and plot sheets to calculate and visualize key system reliability metrics such as:

  • Reliability and probability of failure
  • Reliable life (i.e., time for a given reliability)
  • BX% life (i.e., time for a given unreliability)
  • Mean life
  • Failure rate

Minimal cut sets: For each analytical diagram, BlockSim identifies the unique combinations of component failure that can cause system failure. These minimal cut sets can be used to understand the structural vulnerability of a system.

Identify critical components: FRED Reports (Failure Reporting, Evaluation and Display) provide an intuitive graphical presentation of key metrics, with color-coding to identify the ones that may be critical for system improvement. FRED reports are available for analytical and simulation diagrams.

Reliability importance plots: BlockSim provides a set of Reliability Importance plots designed to show the relative importance of each component with respect to the overall reliability of a system.

Optimum Reliability Allocation

Dedicated tool to help you find the most effective reliability allocation to meet a system’s reliability goal

This feature supports Equal, Weighted and Cost Optimized methods. Start at the system level and click your way to the component or failure mode level while the software automatically computes the target reliability for each item/mode and transfers it to the next.

Availability Analysis via Simulation Diagrams

Flexible and realistic capabilities for reliability, availability, maintainability and supportability analysis of repairable systems

For a new system, you can use simulation results to optimize the design and make projections about how the system may perform in the field. For existing equipment, use the results for maintenance planning, throughput estimates, life cycle cost estimation and more. When you utilize simulation, the analysis can consider:

  • Task scheduling logistics, which includes a “Virtual Age” option for situations in which the scheduled maintenance task will be performed even if the item has failed.
  • Restoration factor that captures the impact of repairs on the future reliability of the component.
  • Duty cycles for components (or assemblies) that experience a different stress load than the rest of the system.
  • Expected downtime associated with corrective or scheduled maintenance.
  • Costs and logistical constraints associated with allocating the personnel (repair crews) and materials (spare parts) required to perform maintenance.
  • Maintenance groups that identify components that will receive maintenance based on what happens to other components.
  • State change triggers that activate or deactivate a block under certain conditions during the simulation. This provides increased modeling flexibility for highly complex dependency scenarios, such as standby configurations and other situations when you may need to divert the simulation onto an alternate path when a particular event occurs.

BlockSim’s simulations generate a wide variety of results at the system and/or component level (such as Uptime/Downtime, Mean Time to First Failure (MTTFF), Availability, Reliability, Number of Failures, Number of PMs/Inspections, Costs, etc.). You can use these results for many different applications, including:

  • Choosing the most effective maintenance strategy based on considerations of safety, cost and/or availability.
  • Using the optimum replacement tool to calculate both the optimum preventive maintenance (PM) and/or optimum inspection intervals.
  • Managing the spare parts inventory based on considerations of cost, utilization rate, supply bottlenecks, etc.
  • Identifying the components that have the biggest impact on availability (downtime).

The software’s Log of Simulations feature provides the information you need to evaluate the variability in specific simulation results of interest.

Life Cycle Cost Estimation

Specify both the direct and indirect costs associated with the maintenance strategies that you have defined, including costs related to downtime, maintenance crews and spares

This yields a wide array of simulation results that are instrumental in performing realistic LCC assessments. With BlockSim’s modeling flexibility, you can:

  • Specify what kinds of crew delays are included in cost calculations and what delays should be ignored.
  • Specify costs associated with system failure, including cost per incident and downtime rate.
  • Specify system uptime revenue and revenue due to throughput so the simulation is able to calculate opportunity costs.
  • View new cost-related simulation results, including system-level costs, the contributions of different kinds of wait times to block costs and the contribution (criticality) of a block’s cost to the total system costs.
Reliability Phase Diagrams (RPD)

Model systems that go through different phases during the course of their operation

For example, some aircraft components operate only during the take-off and landing phases of a mission. Other components may experience a higher failure rate during certain phases due to higher stress.

In addition, the software uses Maintenance Phases to model scenarios in which a system goes directly to maintenance under specified conditions. For example, if a failure during the taxi phase sends an aircraft in for maintenance, it will start over from the beginning of the mission once repaired — not from the middle of the taxi phase where it was when the failure occurred, as other RBD analyses have been forced to assume. This flexibility provides a tremendous leap forward in the ability to simulate system operation more realistically.

BlockSim includes success/failure paths, for situations where a system proceeds to one operational phase upon success and a different operational phase upon failure. Node blocks and stop blocks are included as well.

Throughput Analysis

Identify bottlenecks, optimize resource allocation and improve the processing efficiency of the system

The software allows you to determine how the simulation will allocate the processed output across the paths defined in the diagram. The software also allows you to specify how the backlog will be processed. When the throughput varies over time, BlockSim phase diagrams can be combined with models to describe the time-dependent variability (linear, exponential or power).

“What-if” Scenario Simulation Using Variables

Investigate the effect of one or more variables on the simulation results

The Simulation Worksheets feature allows you to vary values within Reliability Block Diagram and flowchart simulations. Two examples:

  • Design an experiment in Weibull++ —> simulate the experiment in BlockSim or RENO —> then return to Weibull++ and analyze the simulated “response” data.
  • Perform batch simulation of an RBD, using different input values for each simulation. For example, this tool makes it easy to run a set of simulations that compare a variety of possible scenarios by altering specific inputs (e.g., cost, maintenance interval, etc.) for each simulation.
Multi-thread Support and Batch Mode

Improve performance and save time when simulating complex diagrams

In addition to parallel processing, a batch Mode feature improves productivity by allowing you to schedule a series of simulations in advance.

Plots and Reports

Visualize your analysis results through comprehensive post-processing

  • Plot setup allows you to completely customize the “look and feel” of plot graphics while the RS Draw metafile graphics editor provides the option to insert text, draw objects or mark particular points on plot graphics. You can save your plots in a variety of graphic file formats for use in other documents.
  • Overlay plots allow you to plot multiple results together in the same plot. This can be an effective visual tool for many different purposes, such as comparing different analyses (e.g., Design A vs. Design B) or demonstrating the effects of a design change (e.g., Before vs. After).
  • Customizable reports seamlessly integrate spreadsheet and word processing capabilities while enabling you to include calculated results and plots from your analysis

Given you are working as a third party (having to chase the software publishers on our behalf) the speed of resolution and the general contact was excellent.

BMT Defence and Security UK Ltd (Bath)

Your [ReliaSoft] software is extremely user friendly and easy to use. It enables us to make fact based decisions.


... certainly impressed with ReliaSoft products, having had chance to use Weibull++ for themselves, and shared in the analysis of their paper-clip exercise on ALTA PRO. BlockSim just did everything that they would expect.

University of Warwick

I currently use Weibull++, BlockSim & Lambda Predict and am very pleased with the software. I have been an every day user of alternative suppliers’ reliability software and found ReliaSoft to be the most comprehensive and user friendly.

Xyratex Storage Systems

How Can ReliaSoft BlockSim Help Your Reliability Activities?

Our combined software, training and consulting solutions enable you to develop your reliability engineering capabilities within your business efficiently and effectively, with expert support and mentoring from our experienced technical services team.

For more information or to arrange an informal, no-obligation discussion on your requirements, please complete the form opposite or contact us using the details below.

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