Every distributor knows the range is top-heavy. Few have run the numbers on their own data, which is a shame, because the answer changes what you stock, what you promote, and which supplier relationships matter. The analysis takes an hour.
Run it on units, not revenue
The instinct is to rank by revenue. For a stocking decision that is the wrong axis.
A heat exchanger sells for a hundred times what an o-ring does, and it will dominate a revenue ranking while representing a handful of transactions a year. The o-ring is what a service van runs out of on a Friday, and running out of it costs you the whole basket that came with it.
Rank by units first, then look at revenue as a second dimension. What you are protecting against is a stock-out on a part that is cheap, frequently needed, and unglamorous.
The four quadrants
Cross unit volume with unit value and you get four groups that want different treatment:
| High units | Low units | |
|---|---|---|
| Low value | Core stock. Never out. Deep safety stock — carrying cost is trivial against the cost of a stock-out | Long tail. Stock thinly or not at all |
| High value | Managed. Real forecasting, real reorder points | Order in. Do not stock. Quote lead time honestly |
Most of the mistakes are in the two diagonal corners. Distributors over-stock high-value/low-units because the items feel important, and under-stock low-value/high-units because they feel trivial.
The cheap, fast-moving corner is where service customers are won and lost. Nobody changes supplier because you had to order in a heat exchanger. They change supplier because you were out of a $3 seal three times.
What is usually in the core
Every market differs, but the pattern is consistent across pool service work:
- Sealing components. Shaft seals, pump lid o-rings, housing o-rings, diffuser gaskets. Most-replaced items in the trade
- Pump wet-end parts. Impellers, diffusers, seal plates, strainer baskets and lids
- Filter consumables. Clamp assemblies, air relief components, tank o-rings, grid and cartridge hardware
- Valve service parts. Diverter seals, gaskets, valve rebuild components
- Cleaner wear parts. Wheels, tyres, bearings, sweep hoses, covers — high wear by design
The common thread is that these fail because they are supposed to. They are consumables in normal operation, so demand is a function of installed base rather than of anything unpredictable.
Sizing the core
A useful working target: the 150–250 SKUs that cover the majority of your unit volume. Below 150 you will be ordering in too often; above 250 you are carrying the tail.
To find yours:
- Export 24 months of sales, at line-item level
- Aggregate by part number, sum units
- Sort descending, add a cumulative percentage column
- Find where cumulative units crosses 80%
The SKU count at that line is your core. Almost everyone is surprised by how small it is — and equally surprised by how many of those parts they currently order in rather than stock.
Two adjustments the raw ranking will not show
Lost sales are invisible. Your sales history records what you sold, not what a customer asked for and went elsewhere to get. If you have any record of stock-outs or substitutions, overlay it, because those are precisely the parts most worth stocking.
Seasonality distorts a 12-month window. Run 24 months, or the winter tail looks like low demand rather than the other half of a cycle.
What to do with the analysis
For the core: deepen it. These parts have stable demand, so safety stock is easy to justify and stock-out costs are high. This is also where an aftermarket supply relationship earns the most — high volume, price-sensitive, low fitment risk.
For managed: proper reorder points and a real lead-time conversation with your supplier.
For order-in: stop apologising for not stocking them. Quote a lead time and be right about it. A customer who is told five weeks and gets it in four is happier than one told two weeks and getting it in four.
For the long tail: decide whether to list without stocking. Being findable for a part you order in still wins the customer — provided the listing says so honestly.
The reorder question this answers
Once you know your core, MOQ stops being a problem and becomes arithmetic.
A part in your core selling 200 units a year at a 50-piece minimum is a quarterly order — completely routine. The same 50-piece minimum on a long-tail part selling four a year is twelve years of stock, and the right answer is not to stock it.
MOQ is only a constraint when it is applied to the wrong parts. Run the analysis and it mostly resolves itself.
Sourcing
POOLPOINT is built for the core of that range — sealing components, pump wet-end parts, filter and valve service items — at 50 pcs per part with mixed cartons, so a quarterly order can cover twenty SKUs without over-committing on any one. Send us your top 100 by units and we will tell you which we can match and what they cost delivered.