BlockSim Functions

This section presents detailed descriptions of the predefined and internal functions available in BlockSim.

Event Analysis Internal Functions

These functions apply only to event analysis flowcharts. They are used to create string expressions to be evaluated in event analysis functions and static functions, event analysis standard blocks, or as conditional inputs or outputs for conditional blocks, binary nodes, logic gates and branch gates. You can enter these functions manually or select them from the function selector or the equation editor.

  • Event Analysis Internal functions return results from event analysis flowchart blocks, resources and simulations.
  • Diagram Simulation functions return results from simulation definitions. Before you can use these functions, you must first use the simulate function to run a simulation on the RBD or fault tree associated with the simulation definition. Once the simulation definition has been run, you can use each of the "sr_" functions to return a specified result for the diagram associated with that simulation definition.

Event Analysis Predefined Functions

These math-related functions apply only to event analysis flowcharts. You can enter these functions manually or select them from the function selector or the equation editor.

  • General Math functions return results from standard mathematical operations. Note that this section lists only the functions that are unique to event analysis flowcharts. The function selector and equation editor contain many more math functions that are also available in spreadsheets. (See Spreadsheet Functions.)
  • Event Analysis Probability functions return the probability that a random variable will occur. In other words, it returns the value of F(x) given x, where F(x) is the cumulative density function of a distribution. The returned probability will always be between 0 and 1.
    • Example 1: To obtain the value of a Weibull distribution at time 1,000 hours with parameters beta = 1.5, eta = 500 and gamma = 0 you would use the function pr_weibull(1000,1.5,500,0).
    • Example 2: To obtain the probability using a random time value, you would use the function pr_weibull(rand,1.5,500,0) where rand is a predefined function that returns a random value that is greater than or equal to 0, but less than 1.
  • Event Analysis Random Variable functions are the opposite of the probability functions. They return the value of random variables based on a given probability distribution. In other words, it returns a value x, given F(x).
    • Example 1: To obtain the value of a uniform-discrete distribution with parameters a = 1 and  b = 6, and probability = 0.9, you would use the function rv_uniform_discrete(0.9,1,6).
    • Example 2: To use a random probability value for the given distribution, you would use rv_uniform_discrete(rand,1,6), where rand is a predefined function that returns a random value that is greater than or equal to 0, but less than 1.

Note throughout that although arguments or inputs are shown here separated by a comma and a space for ease of reading, no space should follow the comma in actual use. If your regional settings use a comma as the decimal separator, a semicolon will be used to separate function arguments (e.g., pr_beta(0,3; 8; 10).

Spreadsheet Functions

These functions are available in the ReliaSoft Workbook's spreadsheet module and in event analysis flowcharts.

  • Spreadsheet Data Source functions are used only in ReliaSoft Workbooks. They return values that are based on an analyzed or simulated diagram. Use the Function Wizard for data sources to access these functions.

Syntax: RELIABILITY(Data_Src,Mission End Time)

Example: =RELIABILITY("RBD!RBD1",5000) returns the reliability of the system in RBD1 at 5,000 hours.

The values returned by these functions are affected by your choice in the Report folio model field on the Analysis Settings page of the diagram control panel. Specifically:

    • All data source functions will return results if you have selected to base the report results on the fitted model. This applies to both analytical and simulation diagrams.
    • For analytical diagrams, all data source functions will return results if you have selected to base report results on analytical results.
    • For simulation diagrams, only the USERCOMPANY and USERNAME functions will return results if you have selected to base report results on simulation results.
  • Spreadsheet Simulation functions are used only in ReliaSoft Workbooks. They return values that are based on a simulated diagram. Use the Function Wizard for data sources to access these functions.

Syntax: SIM_SYSTEM_RESULTS (Data_Src,Result ID,[Phase])

Example: =SIM_SYSTEM_RESULTS("Phases!Aircraft",1,2) returns the mean availability (result ID 1) of the system in the phase diagram called “Aircraft” during phase number 2. You do not have to know the result IDs and phase numbers for this function. You can use the input windows provided by the Function Wizard to select the desired result and phase.

  • Spreadsheet Mathematical functions do not require a data source. They perform a variety of mathematical and statistical operations (e.g., sine, pi or averages). All of these functions are available in ReliaSoft Workbooks. Many are also available for use in event analysis flowcharts.In ReliaSoft Workbooks, use the Function Wizard for formulas to access these functions. In event analysis flowcharts, use the Function Selector or Equation Editor. (Note that this help file provides a partial list of the many math functions commonly used in spreadsheets. More math-related functions and their descriptions are available within the Function Wizard.)

Syntax: AVERAGE(Number1,Number2,...)

Example 1: =AVERAGE(10,7,9,27,2) sums the numbers, then divides by 5 to return 11.

Example 2: =AVERAGE(A1:A6) returns the average of the values in cells A1 through A6.

Word Processing Functions

These functions are available in the ReliaSoft Workbook's word processing module in BlockSim. To access these functions, use the Function Wizard for data sources. The selected function must first be inserted into the word processing module before you can change its settings.

  • Word Processing General functions return values that are related to the basic project information (e.g., project name and user name).

Format: [PROJECT]

Example: [PROJECT] returns the current project name.

  • Word Processing Data source functions return values that are based on an analyzed or simulated diagram (e.g., reliability, failure rate and mean).

Format: [RELIABILITY(Source Number)(Time)]

Example: [RELIABILITY(1)(1000)] uses the analysis in associated data source 1 to return the reliability at 1,000 hours.

  • Word Processing Simulation functions return values that are based on a simulated diagram.

Format: [SIM_SYSTEM_RESULTS(Source Number)(Result ID)]

Example: =SIM_SYSTEM_RESULTS(1)(1) uses the analysis in associated data source 1 to return the mean availability (result ID 1) of the system in the phase diagram. You do not have to know the result ID number for this function. You can use the input windows provided by the Function Wizard to select the desired result.

  • Word Processing Table functions return values in a table format that are based on the analysis in a specified data source (e.g., the probability of failure or reliability for all of the components in the diagram, or the system reliability for a given time range).

Format: [TBLREL(Source Number)(Start Time;End Time;Time Increment)]

Example: [TBLREL(1)(100;500;50)] uses the analysis in associated data source 1 to return a table containing calculated system reliability results at 100 hours and every additional 50 hours until 500 hours is reached (i.e., 100, 150, 200, 250, etc.).

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