Validate a simulation model

Based on an existing FMECA System the user can create a simulation scenario. The model of that scenario can then be used for simulation. To be able to run a simulation, simulation-related parameters must be properly filled with real values. To assess whether or not a model is complete and simulation-ready, it must first be validated. Errors and omissions will be indicated so the user can improve the model and try again.

To validate a simulation model, follow these steps:

1. In the FMECA tree, select a FMECA (sub-)system or part you wish to validate

2. Right-click the selected element and select Validate FMECA Model from the context menu

3. Choose one of the sets of rules offered by the validation screen, and click Validate to start validation. More information on how to use validation rules is explained in the section Validation rules.
   
   
   

   If the simulation model contains no errors Asset Strategy Optimization will show a pop-up window with the message " Validation complete and successful". Closing this message will end the validation process.
   
   

Handling validation errors

When errors or missing data are found during validation, the following screen appears:

 Validation results

In the example above several types of errors have been found in the FMECA mode: a failure cause does not have a FBM defined, there is a hidden failure cause, and there are empty tag numbers. By double clicking on one of the results, one can jump straight to the corresponding object in the simulation tree. If the object itself is missing, such as with the example of a missing FBM, jumping will be to the higher level object where the missing object was expected to be.

The user needs to eliminate the cause of each error before retrying validation.

Note: Resolving the errors in the simulation tree will improve the scenario. It will not make changes to original model in the FMECA tree.

Validation rules

Validation rules are an extension to the basic validation function of Asset Strategy Optimization. After composing a system the user can validate whether or not the model is complete. If data is missing or causing violation of the validation rules simulation will fail. An example is a failure without a known distribution number, or a failure without maintenance attached. When such failure would occur, simulation would yield undesired results. Therefore, validation is an important step in simulation.

However, there are also situations where all data are complete, but because of erroneous input settings will lead to undesirable behavior. An example is a failure that occurs every 10 years, but where time notation was mistakenly set to hours instead of years. Failure would therefore occur every 10 hours during the whole simulation period, triggering a large number of failure occurrences, which will obviously greatly impact the simulation.

Note:The option to be able to use validation rules first needs to be activated in Asset Strategy Optimization.

When validation rules have been activated, the following changes will be made:

• There will be validation choice prior to a simulation

• There will be a parameter screen during validation

Validation choice prior to simulation

With validation rules activated, then when starting simulation the following screen will first appear:

Choose one of the following options:

• Yes - To validate using the validation rules.

• No - To validate with only the minimum of required validation rules

• Cancel - To not start simulation and return to the simulation models screen

Validation rules screen

With option validation rules activated, the following screen will appear when validation starts:

The validation rules screen

Asset Strategy Optimization will always apply a number of basic validation rules upon which the user has no influence. On top of that, a list of optional rules can be used (as listed in the screenshot above).

Hidden failure

There are two options available to check prior to start simulation whether or not the model contains hidden failure causes. Hidden failure can be selected for failure causes. When selected, during simulation hidden failure combined with preventive maintenance (inspections) will lead to special behavior. When hidden failure occurs during simulation, this will only be exposed if preventive maintenance (inspection) is also scheduled revealing the hidden failure. After this moment, Asset Strategy Optimization will then expose the effect of the hidden failure in simulation reports starting at the moment it occurred. This is specific behavior the user of the simulation module should be aware of when interpreting the simulation results. The two mentioned validation options can make the user extra aware of the fact that during simulation there will be hidden failure effects.

Hidden failure causes present in model

If this validation option is selected, the result of the validation will indicate whether or not hidden failure is present in the model. This will make the user extra aware of the specific behavior described above when hidden failure occurs.

Hidden failure causes without preventive maintenance

If this validation option is selected, the result of the validation will indicate whether or not hidden failure is present in the model, while no preventive maintenance was modelled together with it. Modelled hidden failure without corresponding preventive maintenance will mean that when the hidden failure occurs, it will not appear in the simulation results.

Validation

There are three options to use the list in the validation screen:

• Maintain application settings: By default, validation will be done with this option activated. This option will activate the rules according to the settings defined by the user in the Options menu (Extra > Options > Validation rules).

• Select all optional validation rules: This option will activate all available validation rules by setting all values in column Active to Yes.

• Select no optional validation rules: This option will set all values in column Active to No. The user can then manually change any of the values if desired, by clicking an option in the Active column.

Click Validate to start the validation based on the settings.