A practical guide to managing inventory kitting and product bundling — including Bill of Materials (BOM) tracking, cost calculations, and software approaches for small businesses.
You sell a gift basket that contains a candle, a bottle of wine, and a handwritten card. When a customer buys it, all three items leave your inventory as one. But in your spreadsheet, you're still tracking them separately.
This is the kitting problem — and it's one of the most common inventory headaches for growing businesses.
First, a quick clarification:
Kitting means assembling multiple individual items into a single sellable SKU. A "starter kit" that contains a tool, batteries, and a case is a kit. You manage individual components as raw inventory, and the kit as a virtual assembly.
Bundling means selling multiple products together at a discount, but each item retains its own SKU. A "buy a laptop, get 30% off a bag" is a bundle. The items ship separately, and stock is deducted individually.
Both approaches increase average order value, but they require different inventory management strategies.
The problem is almost always the same: you're double-counting inventory.
When you have 50 units of Product A and 50 units of Product B, and you create 30 kits from them, do you have:
If you answer the first way, you're counting A and B twice — once as individual items and once as part of the kit. This is the most common and most expensive mistake in kitting.
Every kit needs a Bill of Materials — a simple document that lists every component, its quantity, and its unit cost.
Example BOM for a "Baking Starter Kit":
| Component | Quantity | Unit Cost | Total Cost |
|---|---|---|---|
| Mixing bowl | 1 | €4.50 | €4.50 |
| Measuring cups (set) | 1 | €3.20 | €3.20 |
| Whisk | 1 | €2.10 | €2.10 |
| Recipe card | 1 | €0.30 | €0.30 |
| Cardboard box | 1 | €1.50 | €1.50 |
| Packing material | 1 | €0.40 | €0.40 |
| Total Kit Cost | €12.00 |
With a BOM, you can:
Create a master spreadsheet with:
The formula: MIN(stock_of_component_A / qty_in_kit, stock_of_component_B / qty_in_kit, ...)
This works for businesses with fewer than 50 SKUs and fewer than 10 kits. Beyond that, manual errors become inevitable.
Most modern inventory systems handle kitting automatically. When you define a kit:
Look for these features specifically:
For high-volume kits, pre-assemble physical stock and track them as a distinct SKU. This simplifies sales but creates a different challenge: you must maintain two sets of stock records.
This approach works best for seasonal products, subscription boxes, and retail displays.
Here's a scenario we see constantly:
A business sells a gift basket for €40. The visible cost of goods is around €22 — looks like 45% margin. But the real margin tells a different story:
The solution: include labor, waste, and packaging in your kit cost calculation from day one. Adjust your kit price to reflect the real cost of assembly, not just component costs.
If kitting feels too complex for your current stage, start with bundling. Bundles are easier because:
Bundle management requires just two things:
Most ecommerce platforms handle bundling natively (Shopify's "Buy X Get Y" discounts, for example). The risk is that inventory doesn't sync across channels — you sell a bundle on Shopify and forget to deduct from Amazon.
You're ready for kitting when:
At this point, the time savings from proper kit management exceed the setup cost.
Week 1: Create BOMs for your top 5 selling kits using a spreadsheet. Verify the math — do your component counts actually match what goes into each kit?
Week 2: Identify the biggest cost driver in each kit. Is there a cheaper alternative? A bulk discount opportunity? Can you pass the cost to the customer with a premium version?
Week 3: Evaluate whether your current workflow (spreadsheets, manual, or partial software) supports the next 6 months of growth. If not, prioritize inventory software with kit management.
Week 4: Test a new bundle using existing SKUs. Track the impact on average order value and component depletion rates.
Ready to simplify your kitting workflow? Fluxventory tracks component-level inventory automatically, with real-time kit calculations, BOM management, and multi-channel sync. Try it free — no hardware needed, works on any device.
Join businesses using Fluxventory to track stock in real time, reduce losses, and make smarter decisions.