Failure Simulation and Responses User Guide — Introduction and Workflow

Version: 3.9.1

1 Nomenclature

Term	Definition
MADE	Maintenance Aware Design Ecosystem
FCM	Fuzzy Cognitive Maps
FMEA	Failure Modes and Effects Analysis
LOI	Level Of Indenture
PHM	Prognostics & Health Management

2 Introduction

There are many analyses in MADE that are dependent upon the simulation of failures that propagate through the model. For example, the FMEA reports on failure causes, simulates those failures, and records the responses of the system to the failures. Likewise, the diagnostics analysis in the PHM Module uses the propagation table containing item's responses to failures to optimize sensor placement.

As such, understanding how the MADE model is used for failure analysis is important when it comes to interpreting the results of MADE's analyses. At its simplest, the process of failure simulation in MADE is one where a failure is introduced into the model via the perturbation of a flow property and the responses of the other items in the system are recorded. In reality, this is a more complex process that is explored in this document.

Note that this document does not discuss the mathematical details of FCM or Bond simulation in detail — other guides cover such details (see the FCM Modeling Background and Bond Modeling Guide knowledge base files). This guide is focused on the general process for establishing a model's nominal baseline, perturbing the model to simulate a failure, and finding the response to failure across the system.

3 Failure Simulation Workflow

Figure 1 ("Failure Simulation Workflow") depicts "WF08: Conduct Failure Simulation":

Pre-requisites:

• A. FBD Model: to inject failure(s) and propagate throughout, producing failure simulations.
• B. Failure Diagram: FFMs at the minimum, supplemented by failure conditions as required. Simulation and criticality parameters should be defined for failure concepts and connections.

Flowchart steps:

1. Access Failure Injection
2. Inject Failure (fed by: 'Up' Failure, 'Down' Failure, Perturb by Value)
3. Control Failure Simulation
4. Inject Another Failure? → Yes: loop back to step 2 / No: continue
5. Run Failure Simulation
6. Review Step Table → Step Table (output)
7. Review Response Simulation → Response Graph (output)
8. Failure Simulation Conducted

Detailed Descriptions:

1. Select model item and access 'Failure Injection' via the right-click context menu.
2. Inject failure by selecting 'Up', 'Down' or Perturb by Value on any given component.
3. Use the shortcut icons in the toolbar to control the failure simulation.
4. Inject another failure at the necessary time step, if more complex failure simulations are required.
5. Run the failure simulation until equilibrium with the shortcut icons in the toolbar.
6. Access and review the resultant Step Table, which is a tabulated representation of the failure simulation.
7. Access and review the Response Simulation Graphs due to your injected failure(s), which are visual representations of the failure simulation.
8. Failure Simulations conducted, validates the model for further analyses.

Outputs:

• Step Table: tabulated representation of the failure simulation, exported as a .csv file.
• Response Graph: visual representation of the failure simulation, exported as a .png file.