Introduction to the GoldSim Reliability Module

1. Introduction to the GoldSim Reliability Module GoldSim Technology Group Issaquah, Washington USA

2. What is the Reliability Module? • Extension to the standard GoldSim software • Allows you to construct models predicting the performance of complex engineered systems • There are two versions of the reliability module: • RL Learner Edition (included with Basic GoldSim but limited to 10 reliability elements) • RL Professional

3. Reliability Module Elements • The Reliability Module provides two special elements for building reliability models: • The Function element is used to model components that perform their function over time (e.g., a pump or a battery). • The Action element is used to model components that perform their action instantaneously (e.g., a switch or a relay)

4. What can the Reliability Module be Used for? • Integrating the performance of complex, engineered systems into GoldSim models • Establishing the reliability, availability, and maintainability of a system • Evaluating the effect of different component choices or maintenance practices on reliability • Identifying key sources of unreliability • Modeling the consequences of failure

5. Agenda • We’ll build and expand on a small example and cover many of the basic features of the Function element (the Action element is nearly identical save for the Action trigger and related outputs) • Feel free to follow along on your own machines

6. Reliability Element Properties • Property dialogs are similar to other GoldSim elements • Function and Action elements share many common features

7. Reliability Element Outputs • Both scalar and event outputs • Main output is the element’s current status • StartOperating and StopOperating outputs issue events when the component starts and stops operating • Action element has a number of additional outputs • ActionOK and ActionFailed – emitted each time an action is successful/unsuccessful • NumActionTriggers and NumOK – show the total number of triggered actions and the total number of successful actions

8. Reliability Element Status • The main output of each reliability element has a integer status output that can be referenced by other GoldSim elements. • >0 – failure mode n has occurred • 0 – operating • -1 – unmet internal requirements • -2 – unmet external requirements • -3 – undergoing maintenance • -4 – turned off • -5 – parent not operating • If an element is experiencing multiple states, the highest numbered state is shown

9. Workshop Syllabus • Basic Reliability Modeling Concepts • The Simple Failure Rate • On/Off Triggers • Creating dependencies on other RL elements using logic-trees • Modeling an RL element as a system • Using advanced failure mode options

10. Simple Failure Rate • The element fails according to an Exponential/Poisson distribution • It only ages when it is turned on • It is not repaired unless a Replace action is triggered

11. On and Off Triggers • These allow you to turn the component on and off during the simulation • Work exactly the same way as triggers in basic GoldSim • By default, the component is on at the start of the simulation. You can specify the component is initially off by clearing the “Initial Status is On” checkbox.

12. An Example • Let’s create a pump that has a simple failure rate of 1/30 days. • It’s initially on and then turned off between 25 and 75 days • If the pump moves 600 cubic meters per hour, how much water is pumped in 100 days?

13. Representing Dependencies • In many cases, a component cannot be operated unless a number of other supporting systems are operating (or operable) • These type of systems can be modeled using the reliability element’s logic-tree

14. Turning a Reliability Element into a System • Elements modeled as systems retain all of the features of a reliability element (outputs, failure modes and requirements) • Systems also mimic the capabilities of a container (e.g., other reliability and basic GoldSim elements can be placed inside the system) • Adds a second logic-tree to the element (Internal Requirements)

15. Logic Trees • Logic-trees allow you to specify the conditions that must exist for the component to successfully operate • GoldSim supports both requirements-trees (OK = true) and fault-trees (OK = false)

16. Logic Trees (cont.) • Two classes of logic-tree nodes: • Gate nodes • AND • OR • N-Vote • Variable nodes • Condition • Not • RL Component • Not RL Component

17. Continuing the Example • Let’s add an external dependency that links to a Power Status element • Let’s turn the pump into a system and then add a motor and impeller element

18. Advanced Failure Mode Modeling • An exponential failure mode is often not adequate for modeling the behavior of a complex component • More detailed failure modeling can be done on the Failure Modes page (enabled by clearing the “Use Simple Failure Rate” option)

19. Advanced Failure Mode Modeling • Modes can be added/removed using the Add and Remove buttons • Descriptions of each failure mode can be edited • ID numbers for each failure mode can be any integer between 1 and 99 (remember if a system is affected by multiple modes, the highest numbered mode is displayed) • Parameters will changed depending on the failure mode currently selected • Automatic repair can be specified for each mode (according to an Exponential, Lognormal or Gamma distribution)

20. Continuing the Example • Let’s remove the simple failure mode for the Parent pump element and add a failure mode (with repair) to the motor and impeller inside the pump

21. Reliability Module Results • Reliability results are accessed through a tab in each reliability element • Standard metrics are displayed at the top of the dialog • More detailed results can be accessed through the Analysis Options buttons