Depreciation of assets

I’d like to again suggest some improvements to depreciation:

In addition of ‘depreciated value’, there are other crucial information necessary in order to properly do an amortisation table:

  • end of first period
    this is important as not everybody has [always had] their fiscal year aligned on the calendar year.
  • year fraction basis
    as can easily be seen in spreadsheet functions like AMORLINC, it is important to know what method should be used for determining the first depreciation period’s fraction of the full period.
    What is commonly used is:
    0 or missing - US method (NASD), 12 months of 30 days each
    1 - Exact number of days in months, exact number of days in year
    2 - Exact number of days in month, year has 360 days
    3 - Exact number of days in month, year has 365 days
    4 - European method, 12 months of 30 days each (NB: but starting +1 day after method 0)

For example, in the case presented by (Sebastien https://discuss.tryton.org/t/asset-importing)
his old program uses basis ‘0’ arriving at 170,73 = 230 * (9*30 + 5) / 360
If there is no choice, then clearly basis ‘0’ should probably be used.

Also, at least for the French market, there is need for methods other than ‘linear’ namely ‘digressive’.
That should probably better be detailed in a blueprint.

This is already implemented Allow to set when the depreciation move should be created (#7424) · Issues · Tryton / Tryton · GitLab

The module is designed to easily add its own method.
The current linear is exact number of days in months and years. But if someone wants to add other ways, he should make it a configuration flag on accounting as it would make no sense to use different methods for the same accounting.

Again the module is designed to ease the addition of any custom depreciation method.
I do not think there are anything more to discuss. A patch is needed to only review the implementation.

I beg to differ… it appears after your remark in another topic that the method is yet another, never really encountered before, being linear day by day over the asset’s lifetime.
Can you provide a reference to maybe one accounting package from a major that uses this method?
(preferably in a country

I’d like to add the following to the list:

  • Designation
    This permits to add an information to the asset list, such as the marque/model and licence plate of the vehicule or the serial number of some equipment, etcetera. Most packages today have this.
  • Motif for closing
    This would permit specifying the reason for closing the asset such as ‘scrapped’ or ‘sold’ or ‘replaced’…
    Perhaps this could be managed by a company dependent list of motifs for closing the assets.