FM Library - using the media library

This function is only visible if the option MTTF Correction is activated (see also GUI Settings in Asset Strategy Optimization).

Media library table - adjusting MTTF and predefining effects

In certain situations, there can be factors that influence the mean time to failure. E.g. a pump transporting an aggressive fluid, using NBR as gasket material may fail sooner than one containing water and a gasket material of EPDM. In these situations, the media library table can be used to adjust the initial MTTF based on the determinant values. The Media library table is effective only during a Part merge operation (both the FM Library and during the Apply the FM Library templates operation). This way, the user can quickly build up an asset tree, making use of context information known about the asset Parts.

The media library list is a list with combinations of factors that together can influence the MTTF value of a failure cause. Asset Strategy Optimization supports different factor to be defined, e.g. a combination of media/gasket material. The combination of the two can be defined together with the effect (as a percentage of a reference combination) they will have on a default MTTF value. Refer to the example below.

Apart from the MTTF value, the Media Library table can define preset effect values that will be applied during the merge operation, based on the chosen combination.

In the example below, the determinant values would be a media/gasket material combination, where values such as ammonia/NBR and water/EPDM could be linked to a percentage of the MTTF value filled in in the FM Library. The percentage would be applied as soon as the user merged a FM library Part object to a Part in the FMECA screen, while looking at the determinant value in the FMECA screen and applying the percentage to the MTTF value(s) set in the FM library Part structure. Note also that for the two defined Business Objectives (Safety and Quality), preset values are defined. These values are picked from the Library Business Objectives. The mechanism is shown in detail below.

Defining the Media Library table

To define the Media Library table, perform these steps:

1. Open the Media Library table: FM-Library > Configure Media Library
   

2. Add new entries using the button "Add media type"

3. Remove obsolete media combinations by selecting a row and pressing the button "Remove media type"

4. In the example shown, choose a combination of Media and Material, then add the MTTF Correction factor (%); Optionally choose preset effect values for each Business objective

5. When done, close the screen using the OK button
   
   

Example of determinant table showing two ways of how a combination of Media/Material may influence the MTTF and default Business Objectives values

Effects linked to a Media/Material combination

In the example above, the media/material combination can also predefine the effect values for the various business objectives (here: Safety and Quality). If the media library table is used, then the combination (Here: media/material) will define which effect values will be used when merging a FM library Part with a FMECA tree Part.

Media field in FMECA

As mentioned above, the Media Library table is only effective during a Merge operation. This requires some preparation. Here is how.

If the option MTTF Correction is activated (see also GUI Settings in Asset Strategy Optimization), an additional field (here) called Media will appear in the section General of the Part object in the FMECA tree in the Property Grid. Here, the user can choose whether or not the media library table entry will influence the MTTF value of each underlying MTTF value, when a merge is performed using a Part from the FM Library. If left empty, then there will be no MTTF correction, if a value is chosen, then an MTTF correction will be performed if other preparation steps are made.

Media field that will appear in the Part object (FMECA tree) if MTTF correction function is activated

Warning when changing the Media field

When changing the value of the Media field, the message below will always appear to warn the user that the change in itself will not influence any of the MTTF values. Only during a merge operation will the value of the Media field have its influence.

Warning when changing the value of the Media field

Note: The Media field only has its influence during merge operations. Changing the value of the field will in itself not change any other fields.

MTTF Correction field

If the option MTTF Correction is activated (see also GUI Settings in Asset Strategy Optimization), a new field called MTTF Correction applied will appear in the failure cause object in the FMECA tree, while in the FM Library, a field called Apply MTTF Correction will appear (only in the Property Grid, as shown below). In the FM Library, the user can choose to enable or disable the option for each failure cause. In the FMECA tree, the field will be an indicator whether or not MTTF correction has been applied there.

The option Apply MTTF Correction in the FM library will determine whether or not during a merge operation the MTTF value set here will be corrected based on the Media field value

Effect of Media value on MTTF - MTTF Correction

The following example shows how during a merge operation the MTTF value will be corrected. If you are not familiar with the merge operation, then first consult the FM Library explanation.

On the left, the FM-Library shows two failure causes, conveniently named 'Failure cause without MTTF Correction' and 'Failure cause with MTTF Correction' for the sake of the explanation. The first failure cause has the option 'Apply MTTF Correction' enabled (1), while the second failure cause do not have the option enabled (2). Both failure causes are related to the Part called ´Media FM Part´. In the example, this Part will be merged with the Part called Media Part in the FMECA tree (4). To prepare for this, the Part´s field called Media has been filled with the combination Ammonia-NBR (3).

Example how an MTTF correction is performed based on a filled Media field

Result

After the merge operation the complete Part structure in the FM-Library will have been copied over to the FMECA tree, while the Part fields were (partly) copied over to other side. Note that the field MTTF Correction applied indicates whether or not a correction was actually performed (1). Note also that the original library value of 2 years has been corrected to 80% of that value, i.e. 1.6 years. For the other failure cause (3), no correction was applied, and the original value of 2 years was retained.

Result of the merge example above: one failure cause MTTF value has been corrected, while the other has not

Influence of media field on Effects - Filled effect value

Like in the example above the MTTF value can be corrected during a merge operation, based on a value in the field Media, in the same way the Media value can predefine which effect values will be filled in during a merge operation. Here is how this works in detail.

Business Objectives

Business objectives can be defined both for each FMECA system and for the FM-Library as a whole. If the user wishes to use the FM-Library to quickly set up the asset tree, including auto-filling the effect values, by using a (mass) merge operation, the following rules apply:

• Both in the FM-Library and the target FMECA system the business goals and their effect values must have identical values

• In the Media Library table, appropriate effect values defined for the FM-Library must be chosen for each row

• To prepare for an effect value to be filled in from the Media Library table during a merge operation, instead of fixed value, the special value <media> must be selected in each appropriate Failure Mode (see below).

Choose the special value <media> for each Failure Mode in the FM-Library to make it media dependent

Note: the special value <media> will show up automatically when the option MTTF Correction is activated (see also GUI Settings in Asset Strategy Optimization)

Example of Effects values during merge

The following example shows how during a merge operation, the Effect values defined in the media library table can be used to fill in the failure cause fields in the FMECA tree.

Situation:

6. In the FM Library, there is a Failure cause called Failure cause with Media Effects.  

7. The FM Library Business Objectives define two categories: Safety and Quality. For this Failure cause, we choose the special value <media> to enable the media library table.

8. We must make sure that (part) of the values of the Business Objectives defined for the library and for the FMECA System are identical. In this example, the FMECA system defines two of the three values defined in the Library.

9. In the FMECA system, the Media field of the Part is set to Ammonia - NBR

   Then, the merge operation is performed.

Example of how a merge operation is prepared by using the special value <media>, that will populate the Business Objective effect fields based on the Media Library table

Result

After the merge is complete, the failure causes of the FM-Library Part will appear in the FMECA system on the right. If we select the Failure cause called Failure cause with Media Effect, we will see the following:

10. The MTTF Correction Applied field is checked, so a correction was applied here

11. The MTTF value itself has changed (see the example above about MTTF Correction)

12. Based on the chosen Media value (Ammonia - NBR), the following two values were selected from the Media Library table:

    • Safety : Lethal Effects

    • Quality - No Effect

    The values are shown in the fields of the Failure cause

Example of how effect values from the Media Library table are used to populate the Business objective effect fields of a Failure cause during a merge operation.