Declining Balance, Then Straight Line

Declining Balance, Then Straight Line

Business Central's DB1/SL depreciation method front-loads depreciation with a declining-balance percentage, then switches to straight-line the moment straight-line over the remaining life yields more — and a real fixed-asset ledger must land the book value on the salvage value to the cent, no matter how many periods rounded along the way. You will build that schedule generator, distilled to its core.

Requirements

The starter contains a table "Depr. Schedule Line" and an enum "Depr. Line Method" (values "Declining Balance" and "Straight Line"). Keep both exactly as shipped — the grading tests read the table and reference the enum values by name:

• "Period No." — Integer, the primary key, 1-based
• Months — Integer, the number of months the period covers
• Method — Enum "Depr. Line Method", which formula produced the period's amount
• Amount — Decimal, the period's depreciation, always whole cents
• "Book Value" — Decimal, the book value at the end of the period, always whole cents

Create a codeunit named "Depreciation Scheduler" with one public procedure:

procedure BuildSchedule(var ScheduleLine: Record "Depr. Schedule Line"; AcquisitionCost: Decimal; SalvageValue: Decimal; LifeYears: Integer; DecliningBalancePct: Decimal; FirstYearMonths: Integer): Integer

It writes the complete depreciation schedule into the buffer, one line per period, and returns the "Period No." of the first line whose Method is "Straight Line".

Whenever a rule below says an amount is rounded, it means AL's default Round to 0.01 — to the nearest cent, halves away from zero.