BOM: Bill Of Material

By accessing to RPA > Bill Of Material, the user can choose a project from the RPA and create as many BOMs as required.

Actions

The actions that can be performed on each node of the BOM are:

• Add a child: Action to add an item below a node of the BOM. The fields that are necessary to fill are the same as in FRACAS.

  

• Remove: Delete the node (and all its children) from the BOM

• Calculate failure rate: If it is a node without any children, the failure rate can be assigned from several sources:

  • Manual: The failure rate is entered manually

  • Electronic Prediction: The failure rate is computed with one of the available standards for Electronic Prediction (see EPRP: Electronic Parts Reliability Prediction section)

  • Mechanical Prediction: The failure rate is computed with one of the available standards for Non-Electronic Prediction (see NPRP: Non-electronic Parts Reliability Prediction section)

  Note

  When a calculation is done on a PN which has been already computed, Robin automatically selects and introduces the data corresponding to the first calculation, easening the data introduction for the user, allowing them to focus only on the changes. Furthermore, if there is more than one entry for the same Part Numer in the BOM, e.g. two identical resitors, Robin will ask the user if they want to keep the original value for the rest of items or substitute the failure rate for the recently computed value.

  

  

After computing the failure rate in the corresponding page, Robin gives the option to go back to the BOM. Note that, if the node has children, the computation is performed based on the failure rates of the children (see the RPA | Reliability Prediction Analysis section for computation details).

• Calculate total failure rate: If there is a node with one or severeral children, Robin automatically computes the failure rate of the subassembly by summing all the failure rates of its children.

  Note

  When a calculation is performed in a child, the calculator symbol of its parent turns red to indicate that the value provided for it is not updated.

• Copy part: It copies the node and all its children.

  Note

  This option is useful when the same PN is found in different assemblies or subassemblies

• Copy calculation: This option is only available for last level items, i.e. parts without any children. By clicking in the copy icon, the user will get the option to copy the calculation or the entire part.

  Note

  This option is very useful when the calculation (i.e. standard, component, category, subcategory/ies and parameters) for two items with different PN are the same. In normal situations, these items should have identic PN. However, it might be possible that because the part is in different assemblies, have different PNs. It is in these situations when the current option becomes very useful.

  

• Paste part: When active, it pastes the nodes of the clipboard below the selected node (if the entire item has been copied) or the calculation (if only the calculation has been copied)

  Note

  Calculations can only be copied in last level items.

  Note

  If a calculation has been copied from one item to another, and the user modifies the calculation for any of the two items, Robin will ask if the calculation result is to be updated in the remaining part as well.

  

• Change description and Change Quantity: each changes either the description or quantity of the chosen part.

• Change safety factor: The purpose of assigning a safety factor in a reliability prediction analysis is to provide an additional margin of safety to account for uncertainties, variations, and potential errors in the analysis.

• Add comment: The user can add notes/remarks that will be linked to each item in the BOM

• Copy - Cut - Paste Multiple Items: In order to reduce time consuming actions such as copying or deleting multiple items, Robin incorporates a checkbox (one per item). When clicking the checkbox of those items on which the action is to be made, 3 options will be displayed in the top part of the screen:

  • Copy selected: After copying the desired items, the user can paste them as children on any node by cliking the Paste icon.

  • Cut selected: After cutting the desired items, the user can paste them as children on any node by cliking the Paste icon.

  • Delete selected: By cliking this option, those items which are checked will be deleted

  Note

  Deleting an item does not delete items with equal PN if they have not been checked

  

Moreover, for the top node of the BOM, the following additional actions are also available:

• Import parts: It imports items from a CSV file below the node

• Reliability Prediction Report: It prints a PDF from the BOM.

  When clicked, the following form opens:

  

  In this form, the user can select the sections to be printed. Also, the items can be sorted by failure rate (lower to higher or viceversa) or the order that they appear in Robin website interface. The last option allows the user to choose the level of details in the Component details section (explained below).

  Robin generates the following three sections for this report:

  • System Tree: The hierarchy (levels) of the BOM is presented. Moreover, the overall contribution of each item to the failure rate is also given

    

  • Summary: A summary (without levels) of the failure rate and quantity of each component is presented (including percentages of the individual contributions to the quantity and failure rate). The items that contribute more to the failure rate are highlighted in red.

    

  • Component details: The details of the BOM components, which include the type of component, category, used standard, environment, and temperature

    In case of Basic, the section has the following details:

    

    In case of Extended, the section contains more detailed parameters for each of the analysis:

    

• Export BOM: It exports the entire BOM in CSV or Excel format

• Associate FIDES phases: When clicking it, a table will open on the right side of the screen, allowing to introduce each of the life phases (both operating and non-operating phases) of the assembly for the FIDES computation. The following parameters shall be specified per each FIDES phase:

  • Phase name

  • Is it an operating phase?: The FIDES model applies different parameters for those phases which are operative and those which are not. By clicking the checkbox, Robin will consider that the phase is an operating phase.

  • Cycles per year: Number of cycles associated with each phase over a year.

  • Cycle duration: In hours, indicates the duration of one cycle. By multiplying the cycle duration by how many cycles per year the assembly does, the time associated with each phase over a year is obtained.

  • Average temperature: In degrees Celcius, indicates the average temperature during the phase.

  • Max Temp: In degrees Celcius, indicates the maximum temperature during the phase.

  • Min Temp: In degrees Celcius, indicates the minimum temperature during the phase.

  • Relative Humidity: Percentage indicating the relative humidity during the phase.

  • Vibration: In GRMS, indicates the stress associated with each random vibration during the phase.

  • Saline environment: By clicking the checkbox, Robin will consider that the environment of the assembly during the phase has stronger salinity (e.g. coastal or marine environments)

  • \(\pi_{Application}\): It represents the influence of the usage environment for application of the product containing the item (Ranges from 1 to 10). The user can choose to manually introduce the value of the Pi_Application factor or, by cliking the checkbox, carry out a survey which will automatically calculate the result, even if some questions are not answered.

  • \(\pi_{Ruggedising}\): It represents the influence of the policy for taking account of overstresses in the product development (Ranges from 1 to 2). The user can choose to manually introduce the value of the Pi_Ruggedising factor or, by clicking the checkbox, carry out a survey which will automatically calculate the result, even if some questions are not answered.

  

  Note that the table has 4 buttons below it which allow the user to perform different actions:

  • Close: Closes the table and expands the Bill of Materials.

  • -: Deletes the last phase of the table.

  • +: Adds an empty phase at the end of the table.

  • Save Phases: Stores the data which has been introduced. If there has been an error when introducing data, Robin will raise an alert. If the saving process was correctly performed, a message is displayed in the above the table indicating so and the corresponding parameters that are affected will be recalculated automatically.

Note

Each BOM in the project (level 0 entry) uses its own FIDES table, which is the same for all the BOM.

Warning

It is necessary to define the FIDES associated FIDES before performing a reliability prediction with FIDES. Otherwise Robin will raise an error.

• Change environmental conditions: This option allows you to modify the environmental conditions of a part, which will in turn influence the calculations performed.

Warning

The fields in Manual FR will only affect the calculations of electronic components because of different conversion factors. Meanwhile, MIL-HDBK-217F Notice 2 Calculations uses conversion factors that can be used on other types of components as well.

• See calculation parameters: After clicking this button, the tool will show all the parameters used to compute the reliability of the parts.

Import/Export BOM

By clicking on the icon “Export BOM”, the BOM can exported either in “CSV” or “Excel” format:

Note that the export fields are saved for each user, so that Robin knows which fields to export next time.

The import can be done directly on the BOM by clicking on the “Import parts” icon or by clicking on “Import another BOM”. The appearance of the format is similar to all the imports of Robin. The user can link the columns from the CSV file to the columns of the database.

Note

In the import file, it is necessary to have a column “Level” which tells the hierarchy of the BOM so that Robin knows how to order the parts.

Note

If you import a column called “Quantity”, the program takes the PNs by dividing the “part__PN” by commas (the probability is also divided). If the number of elements does not agree with the specified Quantity, it takes the whole “part__PN” and puts it N times, where N is the specified Quantity

Warning

If a part already exists in your library (same PN), the part from the library will be used.