Simulation fields for Part

Data that can be filled in for a part system are described in "Part" . The fields below are discussed with respect to their role in simulation.

Buffer time

The buffer time is the time required to pass the object's downtime on to the parent object.

Examples of the influence of buffer time

• If an object is down for a period of 1 hour, and the buffer time specified for this object is 4 hours, then the downtime is not passed on to the parent object.

• If an object is down for a period of 4 hours, and the buffer time specified for this object is 1 hour, then the downtime is passed on to the parent object, namely 3 hours.

  Note: Downtime can be caused by both failures and preventive maintenance

The object itself does go down, and will therefore be included in the downtime report; the buffer time only affecting the downtime of parent objects.

Begin date

The value entered for Begin date defines the age of the object at the moment the simulation starts, by subtracting the date the simulation is run ("today") from the Begin date. This implies that planned or scheduled events like failures and preventive maintenance are moved on the simulation timeline. A failure occurring on average after 5 years will now occur 2 years from the start of the simulation, if the date value entered results in a start age of 3 years. The same applies to a preventive maintenance action.

The begin date of a part affects all failures and preventive maintenance actions associated with this object. Only specified Begin dates for a component overrule this value.

Example 1

Suppose a part has a begin age of 3 years. Dependent objects for this system determine that the first preventive maintenance for this part will take place after 5 years. When simulating, the first failure will occur after 4 years.

Example 2

When the begin age entered exceeds the average time of an event, the average time, i.e. the modulus of the start age and event time, is used. Suppose a failure occurs every 3 years on average, and the object has a start age of 10 years.

Then the formula is: MTTF = MTTF - (Start Age of Modulus MTTF). In this example, this is 2 years.

At the moment of simulation, there have, on average, already been 3 failures (after 9 years). So, at the start of the simulation (10 years), it will take another 2 years before the 4th failure is supposed to occur (4 * 3 = 12 years).

Multiple & Length Counter

You can apply the Multiple and Length function to an object when for example a system or subsystem has a large number of identical parts. To all objects which together form one multiple and length object, the following applies:

• The failure data is identical

• The failure behavior is independent

When applying the Multiple & Length Counter function, please understand that downtime differences may arise in comparison to individual object modeling. In the case of individual object modeling, it may occur that failures and maintenance actions coincide, which in turn may result in a reduced downtime. If the object is modelled as Multiple & Length Counter, this will not be the case.

Tip: We recommend that you only use the Multiple & Length Counter parameter when you have become sufficiently familiar with Asset Strategy Optimization.