Scoring mechanism

In the case of coincidental maintenance, the simulation core uses a scoring mechanism to determine which of the coinciding maintenance actions will be used next to assign the next downtime to. By assigning a score to each coinciding action, the simulation core creates a ranking among the coinciding actions for a specific segment. Downtime will be assigned to the action with the highest score.

The scoring mechanism is explained in the following diagram. This diagram is based on values assigned to the variable Maintenance Effect. These values are explained next.

Maintenance Effect

A failure based maintenance (FBM) action can have the following effects, which is stored in variable Maintenance Effect:

• Down: This will cause 100% downtime, regardless of any function loss that is defined on the failure cause

• Out of order: This will take the percentage of function loss for the failure cause into account. This can be regarded as maintenance outside of production hours, which is usually more expensive in terms of labor cost, and therefore gets a higher score (+1) as opposed to No Effect.

• No effect:  This will behave the same as out of order, where this maintenance can take place within production hours (but will not get a higher score of +1)

Any other maintenance action can have the following maintenance effects:

• Down: This will cause 100% downtime, regardless of any function loss that is defined on the failure cause

• Out of order: This will cause 0% downtime, regardless of any function loss that is defined on the failure cause

• No effect:  (same as Out of order)

Both the decision tree and the scoring mechanisms control how downtime will be logged. The next paragraph describes two examples.