Why we organise parts by machine, not by system
Parts catalogues are usually built the way an engineer thinks: engine, fuel, cooling, electrical, chassis. Buyers do not arrive that way. They arrive with a machine.
Five families, with systems underneath
So we start from the machine and treat the systems as coverage beneath it:
| Family | Typical coverage |
|---|---|
| Passenger cars | Engine · Chassis · Electric · Body |
| Trucks & commercial | Engine · Chassis · Electric · Injection |
| Agricultural | Engine · Injection · Electric · Chassis |
| Construction | Engine · Injection · Hydraulic seals |
| Marine | Engine · Injection · Electric |
Why it matters more than it sounds
The same engine turns up in machines that have nothing else in common. An engine that powers a medium truck also sits in an excavator and a generator set — the block is shared; the cooling pack, the mounts and the accessory drive are not. Start from the system and you can find a part that fits the engine but not the installation. Start from the machine and that whole class of mistake disappears.
What this means when you send a list
- Lead with the machine family and model, then the engine identification. Both, not either.
- If a line is shared across families — a bearing set, a gasket — say which machine it is going on. It changes which variant we quote.
- If you run a mixed fleet, group the list by machine rather than by part type. It quotes faster and it ships cleaner.
And when you already have the number
None of this is a detour if you are holding an OEM reference — search it directly and the family sorts itself out. The machine-family route is for the far more common case where you have a machine and a symptom, not a number.