Maintenance - tab General

FIELD

DESCRIPTION

Number

The number by which this maintenance is known may be entered here.

Note: The Number field, when entered, will appear together with the Description field in the FMECA tree, if the option ShowMaintenanceNumberInTree has been set to true in the configuration file.

Note: If more than one similar maintenance objects are created under the same failure cause, while the option IsTreeviewSortingClmByMaintNrActive is set to true in the configuration file, then these similar objects will be displayed sorted in alphabetical order.

Tip: Filling the Number field with a value will sometimes add a leading space. Ordering may seem to fail in this case. To solve this problem, remove the leading space and refresh the tree.

Tip: After changing the Number field the sorting order will not be refreshed automatically. Manually refresh to tree view by first selecting the failure cause object and pressing the F5 button (refresh).

Description

Description of the maintenance action (free text)

Strategy

The selected maintenance strategy is displayed in this field. This is fixed data and cannot be changed. For other maintenance actions, the selected strategy will be displayed accordingly. For example UBM action = UBM, CBM action = CBM, etc.

Maintenance Effect

This field determines whether the availability of a part will be affected while the maintenance action is being carried out. The user has the choice of entering the options, "Down", "No effect", and "Out of service".

• "Down" denotes that the part or component under consideration cannot function during maintenance, which will affect production loss costs (if enabled). If this setting is chosen, in case of simulation and spare part analysis, the value for function loss of the corresponding failure will be always be taken to be 100%. I.e. all of the downtime indicated will be taken into account, while the production loss of the Model will be fully linked to the downtime of this part or component.

• "No effect" denotes that the part or component under consideration will not be hindered by this maintenance action, and operational service should not be affected during maintenance. To express this behavior correctly during simulation and spare analysis, the user should set the field function loss in the corresponding failure cause to 0%. When using this option, for simulation and spare part analysis, the value for function loss of the corresponding failure cause will be used

• "Out of service" denotes that any maintenance will cause (partial) downtime of the system. How much downtime (and corresponding production loss) will be caused is indicated by the field function loss in the corresponding failure cause (in %). During simulation and spare part analysis the function loss will be used to calculate the downtime and production loss.

Maintenance Time

Duration of the maintenance action

Distribution

Type of statistical distribution.

• Normal distribution (average value and variation)

• Exponential distribution (average value)

• Weibull distribution (average value, variation and minimum lifespan)

• Log-normal distribution (average value and variation)

• Fixed distribution (average value)Fixed distribution (average value)

Maintenance Action

Select from Replace part, Replace component or Repair.

Condition Loss

Percentage by which the condition is reduced after the maintenance action. This is expressed as a reduction in the MTTF time of the component in question.

Note: Condition Loss only has an effect on simulation when the value in field Maintenance Action is Replace component (for other values this value will be ignored). This enables simulation of the use of B-components as spare parts: when exchanging a failing component with a B-component of less quality, the MTTF will be sooner.

Example: A failure cause of 10 years with a condition loss of 25% will happen in year 11 and then again after (10yr-25%=) 7.5 years. So, the next failure will be in year 18 (11+7.5). The simulation will compute with the same reduced MTTF (i.e. 7.5 yrs in this example).

Remark: Although field Condition Loss is also used in a UBM action that is directly linked to an object, in that case simulation will ignore the field.

Mandatory

This field can be set to indicate that the modeled maintenance is mandatory, e.g. because of legislation. Marking it as mandatory is a signal that the maintenance should not be changed or removed without careful consideration.