I happened to work on this functionality and thought of sharing the information I gathered on this feature.

Hope you will find it useful.

• Previously it was called "Component requirement calculation" (BOMRET).
• This functionality is closely related to the view provided by the Multilevel BOMS function for both Manufacturing and subcontracting bills of material (BOMs).
• It is used to establish which jobs need to be raised through several levels of a BOM structure, as well as the purchasing requirements required to complete the build.
• All sub-assemblies and components are processed, with the program multiplying the quantity by the net requirement of the parent.
• It provides functionality that can calculate production capacity for a specific date based on real-time available stock. 
• The maximum quantity that can be produced immediately is provided as well as the FDMA, i.e., the first date when the quantity required could be available.
• It checks whether there are enough stock to make BOMS.
• It identifies and displays any potential shortages.
• This result is then compared to the net quantities on hand to determine any shortages.
• Currently only production and or purchase lead times are taken into consideration. If the product site has both then they are not added together.

 Trial kitting function can be accessed from the following functions.

1. In Stock, Inquiries, Stock, Trial kitting

2. In Common data, BOMs,

• Production BOMs

• Subcontracting BOMs

• Commercial BOMs

• Mutilevel BOMs

3. In Sales, Orders, Orders click on the 'Actions' icon.

What information can be entered in Trial kitting?

Selection criteria:

• Storage site
• BOM type
• BOM code
• Reference date – used to control the BOM version and validity.
• Parent product – multiple parent products can be selected.
• Calculation quantity – This field is used to indicate the calculation quantity needed for a parent product and the result screen will display if you have enough components or some of them are short.

Additional selections can be made based on processing mode, sort criteria and the display parameters.                                                   

   Processing mode:

• 1^st level
• Last level
• Multilevel
• Multilevel cumulative

   Sort criteria:

• By product
• By level + parent product
• By level + product
• By BOM (only when there is a single product)

   Display parameters:

• BOM status
• STK link quantity
• Product status
• Lead time
• % scrap
• First availability date

You can either view the results on the screen or view it as a report (BOMRET).

Note:

• If the same component is used for multiple parent products, an asterisk appears in place of the parent product information.
• Based on the above selection criteria’s each component can appear only once.

Maximum build quantity:

• If a shortage appears on a component line, the maximum build quantity is 0.
• If not, the calculation is as follows:
  • Available quantity / (requirement quantity/calculation quantity)
• It takes the lowest value per component to determine the maximum build quantity.
• If component stock unit allows for decimals, it rounds the lowest last decimal.
• If components allow negative stock levels, and a component has a negative quantity, then the maximum build quantity is 0.
• If the include all levels check box is selected, the calculation is done with phantoms or semi-finished product quantity in available stock.
• If a phantom or semi-finished product part is in the BOM, then the components at the next level are not used for the part if there is enough stock for both.
• If not, the phantom and the component at the next level down are used.
• If the include all levels check box is not checked, the calculation is done without phantom or semi-finished product quantity in stock, only with the component stock for the phantom or semi-finished product available.