Modeling Resources in the Reliability Module

Sometimes desired actions can be constrained by Resource availability. For example, if a system component failed, its repair might not be possible until a mechanic and an appropriate spare part were available. In this case, the pool of mechanics and the stock of spare parts would be considered as Resources. Some resources, such as spare parts, are consumed when they are used. Others, such as mechanics, are only borrowed, and become available again once they are no longer required.

One of the advanced features in GoldSim is the ability to create and interact with Resources. Within GoldSim, a Resource is defined as something that has a limited supply (e.g., spare parts, fuel, skilled personnel, money) and is required in order for elements of the modelled system to carry out certain actions.

Using Resources involves three different steps:

• You must define a Resource Type (e.g., Gasoline, Electricians, Pump Motors) and specify its characteristics (discrete or continuous).

• You must specify where the Stores for that particular Resource exist in your model. Stores represent stockpiles or places where the actual Resource (e.g., parts, personnel) is stored or located when not being used. That is, Resource Stores can be thought of as having physical locations in the system you are modeling.

• You must specify how particular elements in the model interact with (consume, borrow from, or add to) the Resource Stores. Only certain kinds of elements can interact with Resources.

Elements can interact with a Resource Store in three different ways:

• An element can Spend (consume) a Resource from the Store.

• An element can Borrow a Resource from the Store for a particular amount of time and then return it.

• An element can Deposit (generate) a Resource into a Store.

Only certain kinds of elements in GoldSim can interact with Resources. The table below summarizes how Reliability elements can use Resources:

Element	Resource Store Interaction	Allowed Usage	Comments
Functions and Actions	Turn Component On: Interacts when component is turned On via the On Trigger	Spend (discrete) Borrow (discrete) Deposit (discrete)	If Requirement is Spend or Borrow, and Resource is not available, the trigger is “held”, and waits for the Resource to become available. Borrowed Resources are returned when the component is turned Off.
Functions and Actions	Replace Component: Interacts when component is Replaced via the Replace Trigger	Spend (discrete)	If Resource is not available, the trigger is “held”, and waits for the Resource to become available.
Functions and Actions	Repair Failure Mode: Interacts when component is automatically repaired via the Resources button on Failure Modes dialog	Spend (discrete) Borrow (discrete)	If Resource is not available, the trigger is “held”, and waits for the Resource to become available. Borrowed Resources are returned when the repair completes.
Actions	Trigger an Action: Interacts when the Action is triggered via the Action Trigger	Spend (discrete) Borrow (discrete) Deposit (discrete)	If Requirement is Spend or Borrow, and Resource is not available, the trigger is “held”, and waits for the Resource to become available. Borrowed Resources are returned when the Action completes.
Functions and Actions	Operate the Component: Interacts while component is operating via the Resources button on main dialog	Spend Rate Deposit Rate	While component is operating, spends or borrows at specified rate. If Spend Rate is specified and Resource is not available, the component stops operating. It resumes when enough Resource is available to cover the next timestep.