Related Topics:

RCM Analysis

Task Manager

Maintenance Task Selection Logic

Simulation and Cost Calculations

Task Properties

In Synthesis applications, maintenance activities are represented using shared resources that are available for use throughout the project and can be managed via the Resource Manager. There are two basic kinds of tasks, which comprise four task classes:

Tasks are assigned to URDs, which are in turn used to represent a set of properties that can be applied to items in the System panel and to functions, failures and causes in the Analysis Panel.

The Maintenance Task window allows you to create, view and edit all classes of maintenance tasks. It can be accessed by double-clicking a task in the FMEA hierarchy or by clicking the Create New or View/Edit icon in the Task wizard, which is accessed from Task fields (e.g., the Corrective Maintenance Task field in the Universal Reliability Definition window).

  

It can also be accessed from the Corrective Tasks and Scheduled Tasks pages of the Resource Manager by choosing Home> Edit > New, by selecting a task and choosing Home > Edit > View or by double-clicking a task.

For a new resource, a name will be proposed automatically based on the default naming criteria established for the current database (See Define Default Name Formats window). You can replace this with your own name of up to 150 characters, if desired. Remember that the name and identifiers are the primary way in which your team will be able to find the Synthesis resources you need for your analyses.

The following options must be configured for all classes of tasks. Configuration options that are specific to particular task classes are presented in the corresponding sections.

What's Changed? In previous versions, task types and the cost calculation methods associated with them were defined via the task selection logic. In Synthesis, task types are defined via the Task Types window and the cost calculation method used for each is determined by the task type's association with a task class.

If no crew is assigned, it is assumed that the work will be done by some undefined crew that is always available.

For simulation, the application uses the restoration factor to determine the new age of the item after the maintenance action.

For example, consider an automotive engine that fails after 6 years. If the engine is rebuilt and the rebuilding task has a 50% restoration factor:

The engine fails again after 3 years (when it again reaches the effective "age" of 6 years), but the rebuild this time affects only the age accumulated after the first rebuild. Thus the engine has an effective age of 4.5 years after the second rebuild (3 + 3 x (1 - 0.5) = 4.5).

After the second rebuild, the engine fails again after a period of 1.5 years (when it again reaches the effective age of 6 years) and a third rebuild is required. The effective age of the engine after the third rebuild is 5.25 years (4.5 + 1.5 × (1 - 0.5) = 5.25).

The engine fails again after 3 years (when it again reaches an effective age of 6 years) and another rebuild is required. This rebuild also rejuvenates the engine by 50%, thus making it effectively 3 years old again.

After the second rebuild, the engine fails again after a period of 3 years (when it again reaches the effective age of 6 years) and a third rebuild is required. The effective age of the engine after the third rebuild is 3 years.

Compare the following tables to see how the two options differ.

Only Damage Accumulated Since Last Repair

Time

Time Since Last Repair

Effective Age Before Repair

Effective Age After Repair

Start = 0

0

0

0

6 years

6

6

3

9 years

3

6

4.5

10.5 years

1.5

6

5.25

 

All Accumulated Damage

Time

Time Since Last Repair

Effective Age Before Repair

Effective Age After Repair

Start = 0

0

0

0

6 years

6

6

3

9 years

3

6

3

12 years

3

6

3

The ReliaWiki resource portal has more information on restoration factors at: http://www.ReliaWiki.org/index.php/Repairable_Systems_Analysis_Through_Simulation#Imperfect_Repairs.

You can collapse or expand all nodes in the hierarchy using the Collapse All and Expand All icons.

  

You can resize the columns by pointing to the column splitter. When the pointer becomes a double-headed arrow, drag the splitter to the desired location. You can restore the column widths to their original settings by clicking the Restore Column Widths icon.

For an existing resource, a link at the bottom of the properties window indicates how many times it is currently being used. If you need more information, click the link or the Trace Usage icon.

This opens the Dependency Viewer, which allows you to explore both where the resource is being used and what other resources are associated with it.

 

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